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TLDR: smartctl (tldr-pages)

Monitor disk health including SMART data.

  • Display SMART health summary
    sudo smartctl {{-H|--health}} {{/dev/sdX}}
  • Display device information
    sudo smartctl {{-i|--info}} {{/dev/sdX}}
  • Start a short/long self-test in the background
    sudo smartctl {{-t|--test}} {{short|long}} {{/dev/sdX}}
  • Display the self-test log
    sudo smartctl {{-l|--log}} selftest
  • Display current/last self-test status and other SMART capabilities
    sudo smartctl {{-c|--capabilities}} {{/dev/sdX}}
  • Display exhaustive SMART data
    sudo smartctl {{-a|--all}} {{/dev/sdX}}
smartctl(8)
NAME SYNOPSIS DESCRIPTION OPTIONS EXAMPLES EXIT STATUS FILES AUTHORS REPORTING BUGS SEE ALSO REFERENCES PACKAGE VERSION
SMARTCTL(8)                            SMART Monitoring Tools                            SMARTCTL(8)



NAME
       smartctl - Control and Monitor Utility for SMART Disks


SYNOPSIS
       smartctl [options] device


DESCRIPTION
       [This man page is generated for the Linux version of smartmontools.  It does not contain info
       specific to other platforms.]

       smartctl controls the Self-Monitoring, Analysis and Reporting Technology (SMART) system built
       into  most ATA/SATA and SCSI/SAS hard drives and solid-state drives.  The purpose of SMART is
       to monitor the reliability of the hard drive and predict drive failures,  and  to  carry  out
       different  types  of  drive  self-tests.  smartctl also supports some features not related to
       SMART.  This version of smartctl is compatible with ACS-3, ACS-2, ATA8-ACS,  ATA/ATAPI-7  and
       earlier standards (see REFERENCES below).

       smartctl  also  provides  support  for  polling  TapeAlert messages from SCSI tape drives and
       changers.

       The user must specify the device to be controlled or interrogated as the  final  argument  to
       smartctl.   The  command set used by the device is often derived from the device path but may
       need help with the '-d' option (for more information see the section on  "ATA,  SCSI  command
       sets and SAT" below).  Device paths are as follows:

       LINUX:   Use  the  forms  "/dev/sd[a-z]"  for  ATA/SATA  and SCSI/SAS devices.  For SCSI Tape
                Drives  and  Changers  with  TapeAlert  support  use  the  devices  "/dev/nst*"  and
                "/dev/sg*".   For  disks  behind  3ware  controllers  you may need "/dev/sd[a-z]" or
                "/dev/twe[0-9]", "/dev/twa[0-9]" or "/dev/twl[0-9]": see details below.   For  disks
                behind  HighPoint RocketRAID controllers you may need "/dev/sd[a-z]".  For disks be‐
                hind Areca SATA RAID controllers, you need "/dev/sg[2-9]" (note  that  smartmontools
                interacts  with  the  Areca controllers via a SCSI generic device which is different
                than the SCSI device used for reading and writing data)!  For HP  Smart  Array  RAID
                controllers, there are three currently supported drivers: cciss, hpsa, and hpahcisr.
                For disks  accessed  via  the  cciss  driver  the  device  nodes  are  of  the  form
                "/dev/cciss/c[0-9]d0".   For  disks  accessed via the hpahcisr and hpsa drivers, the
                device nodes you need are "/dev/sg[0-9]*".  ("lsscsi -g" is helpful  in  determining
                which  scsi  generic device node corresponds to which device.)  Use the nodes corre‐
                sponding to the RAID controllers, not the nodes  corresponding  to  logical  drives.
                See  the  -d option below, as well.  Use the forms "/dev/nvme[0-9]" (broadcast name‐
                space) or "/dev/nvme[0-9]n[1-9]" (specific namespace 1-9) for NVMe devices.

       if '-' is specified as the device path, smartctl reads and interprets it's own  debug  output
       from standard input.  See '-r ataioctl' below for details.

       smartctl  guesses  the device type if possible.  If necessary, the '-d' option can be used to
       override this guess.

       Note that the printed output of smartctl displays most numerical values in base 10 (decimal),
       but  some  values  are  displayed in base 16 (hexadecimal).  To distinguish them, the base 16
       values are always displayed with a leading "0x", for example: "0xff".  This man page  follows
       the same convention.


OPTIONS
       The options are grouped below into several categories.  smartctl will execute the correspond‐
       ing commands in the order: INFORMATION, ENABLE/DISABLE, DISPLAY DATA, RUN/ABORT TESTS.


       SHOW INFORMATION OPTIONS:

       -h, --help, --usage
              Prints a usage message to STDOUT and exits.

       -V, --version, --copyright, --license
              Prints version, copyright, license, home page and SVN revision  information  for  your
              copy of smartctl to STDOUT and then exits.

       -i, --info
              Prints the device model number, serial number, firmware version, and ATA Standard ver‐
              sion/revision information.  Says if the device supports  SMART,  and  if  so,  whether
              SMART  support is currently enabled or disabled.  If the device supports Logical Block
              Address mode (LBA mode) print current user drive capacity in bytes.  (If drive  has  a
              user  protected area reserved, or is "clipped", this may be smaller than the potential
              maximum drive capacity.)  Indicates if the drive is in the smartmontools database (see
              '-v' options below).  If so, the drive model family may also be printed.  If '-n' (see
              below) is specified, the power mode of the drive is printed.

              [NVMe] For NVMe devices the information is obtained from the Identify  Controller  and
              the Identify Namespace data structure.

       --identify[=[w][nvb]]
              [ATA  only]  Prints  an annotated table of the IDENTIFY DEVICE data.  By default, only
              valid words (words not equal to 0x0000 or 0xffff) and nonzero bits and bit fields  are
              printed.   This  can  be changed by the optional argument which consists of one or two
              characters from the set 'wnvb'.  The character 'w' enables printing of all 256  words.
              The  character  'n' suppresses printing of bits, 'v' enables printing of all bits from
              valid words, 'b' enables printing of all  bits.   For  example  '--identify=n'  (valid
              words, no bits) produces the shortest output and '--identify=wb' (all words, all bits)
              produces the longest output.

       -a, --all
              Prints all SMART information about the disk, or TapeAlert information about  the  tape
              drive or changer.  For ATA devices this is equivalent to
              '-H -i -c -A -l error -l selftest -l selective'
              and for SCSI, this is equivalent to
              '-H -i -A -l error -l selftest'.
              For NVMe, this is equivalent to
              '-H -i -c -A -l error'.
              Note  that  for ATA disks this does not enable the non-SMART options and the SMART op‐
              tions which require support for 48-bit ATA commands.

       -x, --xall
              Prints all SMART and non-SMART information about the device.  For ATA devices this  is
              equivalent to
              '-H -i -g all -g wcreorder -c -A -f brief -l xerror,error -l xselftest,selftest -l se‐
              lective -l directory -l scttemp -l scterc -l devstat -l defects -l sataphy'.
              and for SCSI, this is equivalent to
              '-H -i -g all -A -l error -l selftest -l background -l sasphy'.
              For NVMe, this is equivalent to
              '-H -i -c -A -l error'.

       --scan Scans for devices and prints each device name, device  type  and  protocol  ([ATA]  or
              [SCSI])  info.   May  be  used in conjunction with '-d TYPE' to restrict the scan to a
              specific TYPE.  See also info about platform specific device scan and  the  DEVICESCAN
              directive on smartd(8) man page.

       --scan-open
              Same  as  --scan, but also tries to open each device before printing device info.  The
              device open may change the device type due to autodetection (see also '-d test').

              This option can be used to create a draft smartd.conf file.  All  options  after  '--'
              are appended to each output line.  For example:
              smartctl --scan-open -- -a -W 4,45,50 -m admin@work > smartd.conf

              Multiple  '-d  TYPE' options may be specified with '--scan[-open]' to combine the scan
              results of more than one TYPE.

       -g NAME, --get=NAME
              Get non-SMART device settings.  See '-s, --set' below for further info.


       RUN-TIME BEHAVIOR OPTIONS:

       -j, --json[=cgiosuvy]
              Enables JSON or YAML output mode.

              The output could be modified or enhanced by the optional argument  which  consists  of
              one or more characters from the set 'cgiosuvy':
              'c':  Outputs compact format without extra spaces and newlines.  By default, output is
              pretty-printed.  If used with YAML format, the indentation of arrays is reduced.
              'g': Outputs JSON structure as single assignments to allow the usage  of  grep.   Each
              assignment reflects the absolute path of a value.  The syntax is compatible with gron:
              'json.KEY1[INDEX2].KEY3 = VALUE;'.
              'o':  Includes  the  full  original  plaintext  output  of  smartctl  as  a JSON array
              'smartctl.output[]'.
              's': Outputs JSON object elements sorted by key.  By default, object elements are  or‐
              dered as generated internally.
              'v':  Enables  verbose output of possible unsafe integers.  If specified, values which
              may exceed JSON safe integer (53-bit) range are always output as a number  (with  some
              'KEY')  and  a string ('KEY_s'), regardless of the actual value.  Values which may ex‐
              ceed 64-bit range are also output as a little endian byte array  ('KEY_le').   By  de‐
              fault,  the  additional  elements  are  only  output if the value actually exceeds the
              range.
              'y': [NEW EXPERIMENTAL SMARTCTL FEATURE] Outputs in YAML format.

              The following two arguments are primarily indented for development:
              'i': Includes lines from the plaintext output which print info already implemented for
              JSON output.  The lines appear as strings with key 'smartctl_NNNN_i'.
              'u': Includes lines from the plaintext output which print info still unimplemented for
              JSON output.  The lines appear as strings with key 'smartctl_NNNN_u'.

       -q TYPE, --quietmode=TYPE
              Specifies that smartctl should run in one of the  quiet  modes  described  here.   The
              valid arguments to this option are:

              errorsonly  -  only print: For the '-l error' option, if nonzero, the number of errors
              recorded in the SMART error log and the power-on time when they occurred; For the  '-l
              selftest'  option,  errors  recorded in the device self-test log; For the '-H' option,
              SMART "disk failing" status or device Attributes (pre-failure or usage)  which  failed
              either  now or in the past; For the '-A' option, device Attributes (pre-failure or us‐
              age) which failed either now or in the past.

              silent - print no output.  The only way to learn about what was found is  to  use  the
              exit status of smartctl (see EXIT STATUS below).

              noserial - Do not print the serial number of the device.

       -d TYPE, --device=TYPE
              Specifies the type of the device.  The valid arguments to this option are:

              auto  -  attempt to guess the device type from the device name or from controller type
              info provided by the operating system or from a matching USB ID  entry  in  the  drive
              database.  This is the default.

              test  -  prints  the  guessed  TYPE,  then  opens  the device and prints the (possibly
              changed) TYPE name and then exits without performing any further commands.

              ata - the device type is ATA.  This prevents smartctl from issuing SCSI commands to an
              ATA device.

              scsi - the device type is SCSI.  This prevents smartctl from issuing ATA commands to a
              SCSI device.

              nvme[,NSID] - the device type is NVM Express  (NVMe).   The  optional  parameter  NSID
              specifies  the  namespace  id  (in  hex) passed to the driver.  Use 0xffffffff for the
              broadcast namespace id.  The default for NSID is the namespace id addressed by the de‐
              vice name.

              sat[,auto][,N]  -  the  device type is SCSI to ATA Translation (SAT).  This is for ATA
              disks that have a SCSI to ATA Translation Layer (SATL) between the disk and the  oper‐
              ating  system.   SAT defines two ATA PASS THROUGH SCSI commands, one 12 bytes long and
              the other 16 bytes long.  The default is the 16 byte variant which can  be  overridden
              with either '-d sat,12' or '-d sat,16'.

              If  '-d  sat,auto'  is specified, device type SAT (for ATA/SATA disks) is only used if
              the SCSI INQUIRY data reports a SATL (VENDOR: "ATA     ").  Otherwise device type SCSI
              (for SCSI/SAS disks) is used.

              usbcypress  -  this device type is for ATA disks that are behind a Cypress USB to PATA
              bridge.  This will use the ATACB proprietary scsi pass through command.   The  default
              SCSI  operation  code  is  0x24,  but  although  it  can be overridden with '-d usbcy‐
              press,0xN', where N is the scsi operation code, you're running the risk of  damage  to
              the device or filesystems on it.

              usbjmicron[,p][,x][,PORT]  - this device type is for SATA disks that are behind a JMi‐
              cron USB to PATA/SATA bridge.  The 48-bit ATA commands (required e.g. for '-l xerror',
              see  below)  do  not  work with all of these bridges and are therefore disabled by de‐
              fault.  These commands can be enabled by '-d usbjmicron,x'.  If  two  disks  are  con‐
              nected  to  a  bridge with two ports, an error message is printed if no PORT is speci‐
              fied.  The port can be specified by '-d usbjmicron[,x],PORT' where PORT is 0  (master)
              or  1  (slave).  This is not necessary if the device uses a port multiplier to connect
              multiple disks to one port.  The disks appear  under  separate  /dev/ice  names  then.
              CAUTION:  Specifying ',x' for a device which does not support it results in I/O errors
              and may disconnect the drive.  The same applies if the specified PORT does  not  exist
              or is not connected to a disk.

              The  Prolific  PL2507/3507 USB bridges with older firmware support a pass-through com‐
              mand similar to JMicron and work with '-d usbjmicron,0'.  Newer Prolific firmware  re‐
              quires  a modified command which can be selected by '-d usbjmicron,p'.  Note that this
              does not yet support the SMART status command.

              usbprolific - this  device  type  is  for  SATA  disks  that  are  behind  a  Prolific
              PL2571/2771/2773/2775 USB to SATA bridge.

              usbsunplus  -  this  device  type is for SATA disks that are behind a SunplusIT USB to
              SATA bridge.

              sntjmicron[,NSID] - this device type is for NVMe disks that are behind a  JMicron  USB
              to  NVMe  bridge.   The  optional  parameter  NSID specifies the namespace id (in hex)
              passed to the driver.   The  default  namespace  id  is  the  broadcast  namespace  id
              (0xffffffff).

              sntrealtek  -  [NEW  EXPERIMENTAL SMARTCTL FEATURE] this device type is for NVMe disks
              that are behind a Realtek USB to NVMe bridge.

              marvell - [Linux only] interact with SATA disks behind  Marvell  chip-set  controllers
              (using the Marvell rather than libata driver).

              megaraid,N  - [Linux only] the device consists of one or more SCSI/SAS disks connected
              to a MegaRAID controller.  The non-negative integer N (in the range of 0 to 127 inclu‐
              sive) denotes which disk on the controller is monitored.  Use syntax such as:
              smartctl -a -d megaraid,2 /dev/sda
              smartctl -a -d megaraid,0 /dev/sdb
              smartctl -a -d megaraid,0 /dev/bus/0
              This  interface  will also work for Dell PERC controllers.  It is possible to set RAID
              device name as /dev/bus/N, where N is a SCSI bus number.

              The following entry in /proc/devices must exist:
              For PERC2/3/4 controllers: megadevN
              For PERC5/6 controllers: megaraid_sas_ioctlN

              aacraid,H,L,ID - [Linux, Windows and Cygwin only] the device consists of one  or  more
              SCSI/SAS  or SATA disks connected to an AacRaid controller.  The non-negative integers
              H,L,ID (Host number, Lun, ID) denote which disk on the controller is  monitored.   Use
              syntax such as:
              smartctl -a -d aacraid,0,0,2 /dev/sda
              smartctl -a -d aacraid,1,0,4 /dev/sdb

              Option  '-d  sat,auto+...'  is  implicitly  enabled  to  detect  SATA  disks.  Use '-d
              scsi+aacraid,H,L,ID' to disable it.

              On Linux, the following entry in /proc/devices  must  exist:  aac.   Character  device
              nodes /dev/aacH (H=Host number) are created if required.

              3ware,N  -  [FreeBSD and Linux only] the device consists of one or more ATA disks con‐
              nected to a 3ware RAID controller.  The non-negative integer N (in the range from 0 to
              127 inclusive) denotes which disk on the controller is monitored.  Use syntax such as:
              smartctl -a -d 3ware,2 /dev/sda  [Linux only]
              smartctl -a -d 3ware,0 /dev/twe0
              smartctl -a -d 3ware,1 /dev/twa0
              smartctl -a -d 3ware,1 /dev/twl0 [Linux only]
              smartctl -a -d 3ware,1 /dev/tws0 [FreeBSD only]
              The  first two forms, which refer to devices /dev/sda-z (deprecated) and /dev/twe0-15,
              may be used with 3ware series 6000, 7000, and 8000 series controllers that use the 3x-
              xxxx  driver.   The  devices  /dev/twa0-15,  must  be used with 3ware 9000 series con‐
              trollers,  which  use  the  3w-9xxx  driver.   The  devices  /dev/twl0-15  [Linux]  or
              /dev/tws0-15  [FreeBSD]  must be used with the 3ware/LSI 9750 series controllers which
              use the 3w-sas driver.

              Note that if the special character device nodes /dev/tw[ls]?, /dev/twa?  and /dev/twe?
              do not exist, or exist with the incorrect major or minor numbers, smartctl will recre‐
              ate them on the fly.

              areca,N - [FreeBSD, Linux, Windows and Cygwin only] the device consists of one or more
              SATA disks connected to an Areca SATA RAID controller.  The positive integer N (in the
              range from 1 to 24 inclusive) denotes which disk on the controller is  monitored.   On
              Linux use syntax such as:
              smartctl -a -d areca,2 /dev/sg2
              smartctl -a -d areca,3 /dev/sg3
              The  first  line  above  addresses the second disk on the first Areca RAID controller.
              The second line addresses the third disk on the second Areca RAID controller.  To help
              identify the correct device on Linux, use the command:
              cat /proc/scsi/sg/device_hdr /proc/scsi/sg/devices
              to  show the SCSI generic devices (one per line, starting with /dev/sg0).  The correct
              SCSI generic devices to address for smartmontools are the ones  with  the  type  field
              equal  to 3.  If the incorrect device is addressed, please read the warning/error mes‐
              sages carefully.  They should provide hints about what devices to use.

              Important: the Areca controller must have firmware version 1.46 or later.   Lower-num‐
              bered firmware versions will give (harmless) SCSI error messages and no SMART informa‐
              tion.

              areca,N/E - [FreeBSD, Linux, Windows and Cygwin only] the device consists  of  one  or
              more  SATA  or  SAS  disks  connected  to an Areca SAS RAID controller.  The integer N
              (range 1 to 128) denotes the channel (slot) and E (range 1 to 8)  denotes  the  enclo‐
              sure.  Important: This requires Areca SAS controller firmware version 1.51 or later.

              cciss,N - [FreeBSD and Linux only] the device consists of one or more SCSI/SAS or SATA
              disks connected to a cciss RAID controller.  The non-negative integer N (in the  range
              from 0 to 15 inclusive) denotes which disk on the controller is monitored.

              Option  '-d  sat,auto+...'  is  implicitly  enabled  to  detect  SATA  disks.  Use '-d
              scsi+cciss,N' to disable it.

              To look at disks behind HP Smart Array controllers, use syntax such as:
              smartctl -a -d cciss,0 /dev/cciss/c0d0    (cciss driver under Linux)
              smartctl -a -d cciss,0 /dev/sg2    (hpsa or hpahcisr drivers under Linux)

              hpt,L/M/N - [FreeBSD and Linux only] the device consists of one or more ATA disks con‐
              nected  to a HighPoint RocketRAID controller.  The integer L is the controller id, the
              integer M is the channel number, and the integer N is  the  PMPort  number  if  it  is
              available.  The allowed values of L are from 1 to 4 inclusive, M are from 1 to 128 in‐
              clusive and N from 1 to 4 if PMPort available.  And also these values are  limited  by
              the model of the HighPoint RocketRAID controller.  Use syntax such as:
              smartctl -a -d hpt,1/3 /dev/sda    (under Linux)
              smartctl -a -d hpt,1/2/3 /dev/sda    (under Linux)
              Note that the /dev/sda-z form should be the device node which stands for the disks de‐
              rived from the HighPoint RocketRAID controllers under Linux and under FreeBSD,  it  is
              the character device which the driver registered (eg, /dev/hptrr, /dev/hptmv6).

              intelliprop,N[+TYPE]  -  the device consists of multiple ATA disks connected to an In‐
              telliprop controller.  The integer N is the port number from 0 to 3 of the  ATA  drive
              to  be targeted.  The TYPE can be ata(default), sat, or a USB controller listed above.
              Note: if a type of ATA does not work, try a type of sat.  Use syntax such as:
              smartctl -a -d intelliprop,1 /dev/sda    (under Linux)
              smartctl -a -d intelliprop,1+sat /dev/sda    (under Linux)
              WARNING: The disks are selected by write commands to the ATA  Device  Vendor  Specific
              Log  at  address 0xc0.  Using this option with other devices may have undesirable side
              effects.

              jmb39x[-q],N[,sLBA][,force][+TYPE] - [NEW EXPERIMENTAL SMARTCTL  FEATURE]  the  device
              consists  of  multiple  SATA disks connected to a JMicron JMB39x RAID port multiplier.
              The suffix '-q' selects a slightly different command variant used by some QNAP NAS de‐
              vices.  The integer N is the port number from 0 to 4.
              WARNING: The ATA pass-through commands are issued via READ/WRITE commands to LBA 33 of
              the RAID volume.  Using this option with other devices may overwrite this sector.
              The LBA could be selected in the range 33 (last sector of a GPT) to 62 (last sector of
              traditional boot area).
              By default, access to the device is refused if the selected sector is not zero filled.
              The 'force' flag disables this check.
              WARNING: Original sector data is not written back if smartctl is aborted with  a  sig‐‐
              nal.

              jms56x,N[,sLBA][,force][+TYPE]  -  [NEW EXPERIMENTAL SMARTCTL FEATURE] the device con‐
              sists of multiple SATA disks connected to a JMicron JMS56x USB to  SATA  RAID  bridge.
              See 'jmb39x...' above for valid arguments.

       -T TYPE, --tolerance=TYPE
              [ATA  only]  Specifies  how tolerant smartctl should be of ATA and SMART command fail‐
              ures.

              The behavior of smartctl depends upon whether the command  is  "optional"  or  "manda‐‐
              tory".  Here "mandatory" means "required by the ATA Specification if the device imple‐
              ments the SMART command set" and "optional" means "not required by the ATA  Specifica‐
              tion  even  if  the device implements the SMART command set."  The "mandatory" ATA and
              SMART commands are: (1) ATA IDENTIFY DEVICE, (2) SMART  ENABLE/DISABLE  ATTRIBUTE  AU‐
              TOSAVE, (3) SMART ENABLE/DISABLE, and (4) SMART RETURN STATUS.

              The valid arguments to this option are:

              normal  -  exit  on failure of any mandatory SMART command, and ignore all failures of
              optional SMART commands.  This is the default.  Note that  on  some  devices,  issuing
              unimplemented optional SMART commands doesn't cause an error.  This can result in mis‐
              leading smartctl messages such as "Feature X not  implemented",  followed  shortly  by
              "Feature X: enabled".  In most such cases, contrary to the final message, Feature X is
              not enabled.

              conservative - exit on failure of any optional SMART command.

              permissive - ignore failure(s) of mandatory SMART commands.  This option may be  given
              more  than  once.   Each  additional use of this option will cause one more additional
              failure to be ignored.  Note that the use of this option can  lead  to  messages  like
              "Feature  X  not  supported", followed shortly by "Feature X enable failed".  In a few
              such cases, contrary to the final message, Feature X is enabled.

              verypermissive - equivalent to giving a large number of '-T permissive'  options:  ig‐
              nore failures of any number of mandatory SMART commands.  Please see the note above.

       -b TYPE, --badsum=TYPE
              [ATA  only]  Specifies the action smartctl should take if a checksum error is detected
              in the: (1) Device Identity Structure, (2) SMART Self-Test Log  Structure,  (3)  SMART
              Attribute  Value  Structure, (4) SMART Attribute Threshold Structure, or (5) ATA Error
              Log Structure.

              The valid arguments to this option are:

              warn - report the incorrect checksum but carry on in spite of it.   This  is  the  de‐
              fault.

              exit - exit smartctl.

              ignore - continue silently without issuing a warning.

       -r TYPE, --report=TYPE
              Intended  primarily to help smartmontools developers understand the behavior of smart‐‐
              montools on non-conforming or poorly conforming hardware.  This option reports details
              of  smartctl  transactions  with  the  device.  The option can be used multiple times.
              When used just once, it shows a record of the ioctl() transactions  with  the  device.
              When  used  more  than  once, the detail of these ioctl() transactions are reported in
              greater detail.  The valid arguments to this option are:

              ioctl - report all ioctl() transactions.

              ataioctl - report only ioctl() transactions with ATA devices.

              scsiioctl - report only ioctl() transactions with SCSI devices.   Invoking  this  once
              shows  the  SCSI  commands  in hex and the corresponding status.  Invoking it a second
              time adds a hex listing of the first 64 bytes of data send to, or  received  from  the
              device.

              nvmeioctl - report only ioctl() transactions with NVMe devices.

              Any argument may include a positive integer to specify the level of detail that should
              be reported.  The argument should be followed by a comma then the integer with no spa‐
              ces.   For  example,  ataioctl,2  The  default  level is 1, so '-r ataioctl,1' and '-r
              ataioctl' are equivalent.

              For testing purposes, the output of '-r ataioctl,2' can later be  parsed  by  smartctl
              itself if '-' is used as device path argument.  The ATA command input parameters, sec‐
              tor data and return values are reconstructed from the debug report  read  from  stdin.
              Then  smartctl  internally  simulates  an ATA device with the same behaviour.  This is
              does not work for SCSI devices yet.

       -n POWERMODE[,STATUS], --nocheck=POWERMODE[,STATUS]
              [ATA] [SCSI: NEW EXPERIMENTAL SMARTCTL FEATURE] Specifies if smartctl should exit  be‐
              fore  performing any checks when the device is in a low-power mode.  It may be used to
              prevent a disk from being spun-up by smartctl.  The power mode is ignored by default.

              Note: If this option is used it may also be necessary to specify the device type  with
              the  '-d'  option.  Otherwise the device may spin up due to commands issued during de‐
              vice type autodetection.

              By default, exit status 2 is returned if the device is in one of  the  specified  low-
              power modes.  This status is also returned if the device open or identification failed
              (see EXIT STATUS below).  The optional STATUS parameter allows to  override  this  de‐
              fault.   STATUS  is  an integer in the range from 0 to 255 inclusive.  For example use
              '-n standby,0' to return success if a device is in SLEEP or  STANDBY  mode.   Use  '-n
              standby,3' to return a unique exit status in this case.

              The valid arguments to this option are:

              never - check the device always, but print the power mode if '-i' is specified.

              sleep[,STATUS] - check the device unless it is in SLEEP mode.

              standby[,STATUS]  -  check the device unless it is in SLEEP or STANDBY mode.  In these
              modes most disks are not spinning, so if you want to prevent a disk from spinning  up,
              this is probably what you want.

              idle[,STATUS]  - check the device unless it is in SLEEP, STANDBY or IDLE mode.  In the
              IDLE state, most disks are still spinning, so this is probably not what you want.


       SMART FEATURE ENABLE/DISABLE COMMANDS:

              Note: if multiple options are used to both enable and disable a feature, then both the
              enable  and disable commands will be issued.  The enable command will always be issued
              before the corresponding disable command.

       -s VALUE, --smart=VALUE
              Enables or disables SMART on device.  The valid arguments to this option  are  on  and
              off.

              [ATA]  Note  that the ATA commands SMART ENABLE/DISABLE OPERATIONS were declared obso‐
              lete in ATA ACS-4 Revision 10 (Nov 2015).

              [SCSI tape drive or changer] It is not necessary (or useful) to enable  SMART  to  see
              the TapeAlert messages.

       -o VALUE, --offlineauto=VALUE
              [ATA only] Enables or disables SMART automatic offline test, which scans the drive ev‐
              ery four hours for disk defects.  This command can be given during normal system oper‐
              ation.  The valid arguments to this option are on and off.

              Note  that  the  SMART automatic offline test command is listed as "Obsolete" in every
              version of the ATA and ATA/ATAPI  Specifications.   It  was  originally  part  of  the
              SFF-8035i  Revision  2.0  specification,  but was never part of any ATA specification.
              However it is implemented and used by many vendors.  You can tell if automatic offline
              testing  is  supported by seeing if this command enables and disables it, as indicated
              by the 'Auto Offline Data Collection' part of the SMART capabilities report (displayed
              with '-c').

              SMART provides three basic categories of testing.  The first category, called "online"
              testing, has no effect on the performance of the device.  It is turned on by  the  '-s
              on' option.

              The second category of testing is called "offline" testing.  This type of test can, in
              principle, degrade the device performance.  The '-o on'  option  causes  this  offline
              testing to be carried out, automatically, on a regular scheduled basis.  Normally, the
              disk will suspend offline testing while disk accesses are taking place, and then auto‐
              matically  resume it when the disk would otherwise be idle, so in practice it has lit‐
              tle effect.  Note that a one-time offline test can also  be  carried  out  immediately
              upon  receipt  of  a  user command.  See the '-t offline' option below, which causes a
              one-time offline test to be carried out immediately.

              The choice (made by the SFF-8035i and ATA specification authors) of the  word  testing
              for  these first two categories is unfortunate, and often leads to confusion.  In fact
              these first two categories of online and offline testing could have  been  more  accu‐
              rately described as online and offline data collection.

              The  results  of this automatic or immediate offline testing (data collection) are re‐
              flected in the values of the SMART Attributes.  Thus, if problems or  errors  are  de‐
              tected,  the  values  of these Attributes will go below their failure thresholds; some
              types of errors may also appear in the SMART error log.  These are  visible  with  the
              '-A' and '-l error' options respectively.

              Some  SMART  attribute values are updated only during off-line data collection activi‐
              ties; the rest are updated during normal operation of the device or during both normal
              operation and off-line testing.  The Attribute value table produced by the '-A' option
              indicates this in the UPDATED column.  Attributes of the first type are labeled  "Off‐
              line" and Attributes of the second type are labeled "Always".

              The  third  category of testing (and the only category for which the word 'testing' is
              really an appropriate choice) is "self" testing.  This third type of test is only per‐
              formed  (immediately)  when  a command to run it is issued.  The '-t' and '-X' options
              can be used to carry out and abort such self-tests; please see below for  further  de‐
              tails.

              Any  errors  detected  in  the  self testing will be shown in the SMART self-test log,
              which can be examined using the '-l selftest' option.

              Note: in this manual page, the word "Test" is used in connection with the second cate‐
              gory  just  described, e.g. for the "offline" testing.  The words "Self-test" are used
              in connection with the third category.

       -S VALUE, --saveauto=VALUE
              [ATA] Enables or disables SMART autosave of device  vendor-specific  Attributes.   The
              valid  arguments  to  this option are on and off.  Note that this feature is preserved
              across disk power cycles, so you should only need to issue it once.

              The ATA standard does not specify a method to check whether SMART autosave is enabled.
              Unlike SCSI (below), smartctl is unable to print a warning if autosave is disabled.

              Note that the ATA commands SMART ENABLE/DISABLE AUTOSAVE were declared obsolete in ATA
              ACS-4 Revision 10 (Nov 2015).

              [SCSI] For SCSI devices this toggles the value of the Global Logging Target Save  Dis‐
              abled  (GLTSD)  bit in the Control Mode Page.  Some disk manufacturers set this bit by
              default.  This prevents error counters, power-up hours and other useful data from  be‐
              ing placed in non-volatile storage, so these values may be reset to zero the next time
              the device is power-cycled.  If the GLTSD bit is set then 'smartctl -a' will  issue  a
              warning.   Use  on  to  clear  the  GLTSD  bit and thus enable saving counters to non-
              volatile storage.  For extreme streaming-video type applications  you  might  consider
              using off to set the GLTSD bit.

       -g NAME, --get=NAME, -s NAME[,VALUE], --set=NAME[,VALUE]
              Gets/sets  non-SMART  device  settings.  Note that the '--set' option shares its short
              option '-s' with '--smart'.  Valid arguments are:

              all - Gets all values.  This is equivalent to
              '-g aam -g apm -g lookahead -g security -g wcache -g rcache -g dsn'

              aam[,N|off] - [ATA only] Gets/sets the Automatic Acoustic Management (AAM) feature (if
              supported).   A  value  of  128 sets the most quiet (slowest) mode and 254 the fastest
              (loudest) mode, 'off' disables AAM.  Devices may support intermediate levels.   Values
              below 128 are defined as vendor specific (0) or retired (1 to 127).  Note that the AAM
              feature was declared obsolete in ATA ACS-2 Revision 4a (Dec 2010).

              apm[,N|off] - [ATA only] Gets/sets the Advanced Power Management (APM) feature on  de‐
              vice (if supported).  If a value between 1 and 254 is provided, it will attempt to en‐
              able APM and set the specified value, 'off' disables APM.  Note  the  actual  behavior
              depends  on the drive, for example some drives disable APM if their value is set above
              128.  Values below 128 are supposed to allow drive spindown, values 128 and above  ad‐
              just only head-parking frequency, although the actual behavior defined is also vendor-
              specific.

              lookahead[,on|off] - [ATA only] Gets/sets the read look-ahead feature (if  supported).
              Read look-ahead is usually enabled by default.

              security  - [ATA only] Gets the status of ATA Security feature (if supported).  If ATA
              Security is enabled an ATA user password is set.  The drive will be locked on next re‐
              set then.

              security-freeze  - [ATA only] Sets ATA Security feature to frozen mode.  This prevents
              that the drive accepts any security commands until next reset.  Note that  the  frozen
              mode may already be set by BIOS or OS.

              standby,[N|off]  - [ATA] Sets the standby (spindown) timer and places the drive in the
              IDLE mode.  A value of 0 or 'off' disables the standby timer.  Values from  1  to  240
              specify timeouts from 5 seconds to 20 minutes in 5 second increments.  Values from 241
              to 251 specify timeouts from 30 minutes to 330 minutes in 30 minute increments.  Value
              252 specifies 21 minutes.  Value 253 specifies a vendor specific time between 8 and 12
              hours.  Value 255 specifies 21 minutes and 15 seconds.  Some drives may use  a  vendor
              specific  interpretation for the values.  Note that there is no get option because ATA
              standards do not specify a method to read the standby timer.  If '-s  standby,now'  is
              also  specified, the drive is immediately placed in the STANDBY mode without temporar‐
              ily placing it in the IDLE mode.  Note that ATA standards do not specify a command  to
              set the standby timer without affecting the power mode.
              [SCSI]  [NEW  EXPERIMENTAL SMARTCTL FEATURE] Only the set option with 'standby,off' or
              'standby,0' is accepted and will place the SCSI disk into "ACTIVE" power condition.

              standby,now - [ATA] Places the drive in the STANDBY mode.  This usually spins down the
              drive.   The  setting of the standby timer is not affected unless '-s standby,[N|off]'
              is also specified.
              [SCSI] [NEW EXPERIMENTAL SMARTCTL FEATURE] Only the set option is  accepted  and  will
              place the SCSI disk into "STANDBY_Z" power condition.

              wcache[,on|off]  -  [ATA]  Gets/sets  the volatile write cache feature (if supported).
              The write cache is usually enabled by default.

              wcache[,on|off] - [SCSI] Gets/sets the 'Write Cache Enable' (WCE) bit (if  supported).
              The write cache is usually enabled by default.

              wcache-sct[,ata|on|off[,p]] - [ATA only] Gets/sets the write cache feature through SCT
              Feature Control (if supported).  The state of write cache in SCT Feature Control could
              be  "Controlled  by  ATA",  "Force Enabled", or "Force Disabled".  SCT Feature control
              overwrites the setting by ATA Set Features command (wcache[,on|off] option).   If  SCT
              Feature  Control  sets write cache as "Force Enabled" or "Force Disabled", the setting
              of wcache[,on|off] is ignored by the drive.  SCT Feature Control  usually  sets  write
              cache  as  "Controlled  by ATA" by default.  If ',p' is specified, the setting is pre‐
              served across power cycles.

              wcreorder[,on|off[,p]] - [ATA only] Gets/sets Write Cache Reordering.  If it  is  dis‐
              abled  (off),  disk write scheduling is executed on a first-in-first-out (FIFO) basis.
              If Write Cache Reordering is enabled (on), then disk write scheduling may be reordered
              by the drive.  If write cache is disabled, the current Write Cache Reordering state is
              remembered but has no effect on non-cached writes, which are always written in the or‐
              der  received.  The state of Write Cache Reordering has no effect on either NCQ or LCQ
              queued commands.  If ',p' is specified, the setting is preserved across power cycles.

              rcache[,on|off] - [SCSI only] Gets/sets the 'Read Cache  Disable'  (RCE)  bit.   'Off'
              value  disables  read  cache (if supported).  The read cache is usually enabled by de‐
              fault.

              dsn[,on|off] - [ATA only] Gets/sets the DSN feature (if supported).  The dsn  is  usu‐
              ally disabled by default.


       SMART READ AND DISPLAY DATA OPTIONS:

       -H, --health
              Prints the health status of the device or pending TapeAlert messages.

              If the device reports failing health status, this means either that the device has al‐
              ready failed, or that it is predicting its own failure within the next 24  hours.   If
              this  happens,  use the '-a' option to get more information, and get your data off the
              disk and to someplace safe as soon as you can.

              [ATA] Health status is obtained by checking the (boolean) result returned by the SMART
              RETURN  STATUS  command.   The  return value of this ATA command may be unknown due to
              limitations or bugs in some layer (e.g. RAID controller or USB  bridge  firmware)  be‐
              tween  disk  and operating system.  In this case, smartctl prints a warning and checks
              whether any Prefailure SMART Attribute value is less than or equal  to  its  threshold
              (see '-A' below).

              [SCSI] Health status is obtained by checking the Additional Sense Code (ASC) and Addi‐
              tional Sense Code Qualifier (ASCQ) from Informal Exceptions (IE)  log  page  (if  sup‐
              ported) and/or from SCSI sense data.

              [SCSI tape drive or changer] TapeAlert status is obtained by reading the TapeAlert log
              page.  Please note that the TapeAlert log page flags are  cleared  for  the  initiator
              when  the page is read.  This means that each alert condition is reported only once by
              smartctl for each initiator for each activation of the condition.

              [NVMe] NVMe status is obtained  by  reading  the  "Critical  Warning"  byte  from  the
              SMART/Health Information log.

       -c, --capabilities
              [ATA]  Prints only the generic SMART capabilities.  These show what SMART features are
              implemented and how the device will respond to some of the different  SMART  commands.
              For  example  it shows if the device logs errors, if it supports offline surface scan‐
              ning, and so on.  If the device can carry out self-tests, this option also  shows  the
              estimated time required to run those tests.

              [NVMe]  Prints  various NVMe device capabilities obtained from the Identify Controller
              and the Identify Namespace data structure.

       -A, --attributes
              [ATA] Prints only the vendor specific SMART Attributes.  The Attributes  are  numbered
              from  1  to  253  and have specific names and ID numbers.  For example Attribute 12 is
              "power cycle count": how many times has the disk been powered up.

              Each Attribute has a "Raw" value, printed under the heading "RAW_VALUE", and  a  "Nor‐
              malized" value printed under the heading "VALUE".  [Note: smartctl prints these values
              in base-10.]  In the example just given, the "Raw Value" for Attribute 12 would be the
              actual  number  of  times  that the disk has been power-cycled, for example 365 if the
              disk has been turned on once per day for exactly one year.  Each vendor uses their own
              algorithm  to  convert this "Raw" value to a "Normalized" value in the range from 1 to
              254.  Please keep in mind that smartctl only reports the  different  Attribute  types,
              values,  and thresholds as read from the device.  It does not carry out the conversion
              between "Raw" and "Normalized" values: this is done by the disk's firmware.

              The conversion from Raw value to a quantity with physical units is  not  specified  by
              the  SMART standard.  In most cases, the values printed by smartctl are sensible.  For
              example the temperature Attribute generally has its raw value equal to the temperature
              in  Celsius.   However in some cases vendors use unusual conventions.  For example the
              Hitachi disk on my laptop reports its power-on hours in minutes, not hours.  Some  IBM
              disks track three temperatures rather than one, in their raw values.  And so on.

              Each  Attribute  also has a Threshold value (whose range is 0 to 255) which is printed
              under the heading "THRESH".  If the Normalized value is less  than  or  equal  to  the
              Threshold  value,  then  the  Attribute is said to have failed.  If the Attribute is a
              pre-failure Attribute, then disk failure is imminent.

              Each Attribute also has a "Worst" value shown under the heading "WORST".  This is  the
              smallest  (closest to failure) value that the disk has recorded at any time during its
              lifetime when SMART was enabled.  [Note however that some vendors firmware  may  actu‐
              ally increase the "Worst" value for some "rate-type" Attributes.]

              The  Attribute  table  printed out by smartctl also shows the "TYPE" of the Attribute.
              Attributes are one of two possible types: Pre-failure or  Old  age.   Pre-failure  At‐
              tributes  are  ones  which,  if less than or equal to their threshold values, indicate
              pending disk failure.  Old age, or usage Attributes, are ones which  indicate  end-of-
              product  life from old-age or normal aging and wearout, if the Attribute value is less
              than or equal to the threshold.  Please note: the fact that an Attribute  is  of  type
              'Pre-fail' does not mean that your disk is about to fail!  It only has this meaning if
              the Attribute's current Normalized value is less than or equal to the threshold value.

              If the Attribute's current Normalized value is less than or  equal  to  the  threshold
              value,  then  the  "WHEN_FAILED"  column  will display "FAILING_NOW".  If not, but the
              worst recorded value is less than or equal to the threshold value,  then  this  column
              will  display "In_the_past".  If the "WHEN_FAILED" column has no entry (indicated by a
              dash: '-') then this Attribute is OK now (not failing) and has also  never  failed  in
              the past.

              The  table  column  labeled  "UPDATED" shows if the SMART Attribute values are updated
              during both normal operation and off-line testing, or  only  during  offline  testing.
              The former are labeled "Always" and the latter are labeled "Offline".

              So to summarize: the Raw Attribute values are the ones that might have a real physical
              interpretation, such as "Temperature Celsius", "Hours", or "Start-Stop Cycles".   Each
              manufacturer  converts  these, using their detailed knowledge of the disk's operations
              and failure modes, to Normalized Attribute values in the range 1–254.  The current and
              worst  (lowest  measured) of these Normalized Attribute values are stored on the disk,
              along with a Threshold value that the manufacturer has determined will  indicate  that
              the  disk  is  going  to  fail, or that it has exceeded its design age or aging limit.
              smartctl does not calculate any of the Attribute  values,  thresholds,  or  types,  it
              merely reports them from the SMART data on the device.

              Note that starting with ATA/ATAPI-4, revision 4, the meaning of these Attribute fields
              has been made entirely vendor-specific.  However most newer ATA/SATA disks seem to re‐
              spect their meaning, so we have retained the option of printing the Attribute values.

              Solid-state  drives  use  different meanings for some of the attributes.  In this case
              the attribute name printed by smartctl is incorrect unless the drive is already in the
              smartmontools drive database.

              Note  that the ATA command SMART READ DATA was declared obsolete in ATA ACS-4 Revision
              10 (Nov 2015).

              [SCSI] For SCSI devices the "attributes" are obtained from the temperature and  start-
              stop cycle counter log pages.  Certain vendor specific attributes are listed if recog‐
              nised.  The attributes are output in a relatively free format (compared with ATA  disk
              attributes).

              [NVMe]  For NVMe devices the attributes are obtained from the SMART/Health Information
              log.

       -f FORMAT, --format=FORMAT
              [ATA only] Selects the output format of the attributes:

              old - Old smartctl format.  This is the default unless the '-x' option is specified.

              brief - New format which fits into 80 columns (except in some rare cases).  This  for‐
              mat also decodes four additional attribute flags.  This is the default if the '-x' op‐
              tion is specified.

              hex,id - Print all attribute IDs as hexadecimal numbers.

              hex,val - Print all normalized values as hexadecimal numbers.

              hex - Same as '-f hex,id -f hex,val'.

       -l TYPE, --log=TYPE
              Prints various device logs.  The valid arguments to this option are:

              error - [ATA] prints the Summary SMART error log.  SMART disks maintain a log  of  the
              most  recent  five  non-trivial  errors.   For each of these errors, the disk power-on
              lifetime at which the error occurred is recorded,  as  is  the  device  status  (idle,
              standby,  etc)  at  the time of the error.  For some common types of errors, the Error
              Register (ER) and Status Register (SR) values are decoded and printed  as  text.   The
              meanings of these are:
                 ABRT:  Command ABoRTed
                 AMNF:  Address Mark Not Found
                 CCTO:  Command Completion Timed Out
                 EOM:   End Of Media
                 ICRC:  Interface Cyclic Redundancy Code (CRC) error
                 IDNF:  IDentity Not Found
                 ILI:   (packet command-set specific)
                 MC:    Media Changed
                 MCR:   Media Change Request
                 NM:    No Media
                 obs:   obsolete
                 TK0NF: TracK 0 Not Found
                 UNC:   UNCorrectable Error in Data
                 WP:    Media is Write Protected
              In  addition,  up  to the last five commands that preceded the error are listed, along
              with a timestamp measured from the start of the corresponding power  cycle.   This  is
              displayed  in the form Dd+HH:MM:SS.msec where D is the number of days, HH is hours, MM
              is minutes, SS is seconds and msec is milliseconds.  [Note: this time stamp wraps  af‐
              ter 2^32 milliseconds, or 49 days 17 hours 2 minutes and 47.296 seconds.]  The key ATA
              disk registers are also recorded in the log.  The final column of the error log  is  a
              text-string  description  of  the ATA command defined by the Command Register (CR) and
              Feature Register (FR) values.  Commands that are obsolete in the most current spec are
              listed like this: READ LONG (w/ retry) [OBS-4], indicating that the command became ob‐
              solete with or in the ATA-4 specification.  Similarly, the notation [RET-N] is used to
              indicate that a command was retired in the ATA-N specification.  Some commands are not
              defined in any version of the ATA specification but are  in  common  use  nonetheless;
              these are marked [NS], meaning non-standard.

              The  ATA  Specification  (ATA  ACS-2  Revision 7, Section A.7.1) says: "Error log data
              structures shall include, but are not limited to, Uncorrectable errors, ID  Not  Found
              errors  for  which  the LBA requested was valid, servo errors, and write fault errors.
              Error log data structures shall not include errors attributed to the receipt of faulty
              commands."  The definitions of these terms are:
              UNC  (UNCorrectable):  data is uncorrectable.  This refers to data which has been read
              from the disk, but for which the Error Checking and Correction (ECC) codes are  incon‐
              sistent.  In effect, this means that the data can not be read.
              IDNF  (ID  Not  Found): user-accessible address could not be found.  For READ LOG type
              commands, IDNF can also indicate that a device data log structure checksum was  incor‐
              rect.

              If  the  command  that  caused the error was a READ or WRITE command, then the Logical
              Block Address (LBA) at which the error occurred will be printed in base  10  and  base
              16.   The LBA is a linear address, which counts 512-byte sectors on the disk, starting
              from zero.  (Because of the limitations of the SMART error log, if the LBA is  greater
              than  0xfffffff,  then  either no error log entry will be made, or the error log entry
              will have an incorrect LBA.  This may happen for drives with a capacity  greater  than
              128  GiB  or  137  GB.)   On Linux systems the smartmontools web page has instructions
              about how to convert the LBA address to the name of the disk file containing the erro‐
              neous disk sector.

              Please note that some manufacturers ignore the ATA specifications, and make entries in
              the error log if the device receives a command which is  not  implemented  or  is  not
              valid.

              error  - [SCSI] prints the error counter log pages for reads, write and verifies.  The
              verify row is only output if it has an element other than zero.

              error[,NUM] - [NVMe] prints the NVMe Error Information log.  Only the 16  most  recent
              log entries are printed by default.  This number can be changed by the optional param‐
              eter NUM.  The maximum number of log entries is vendor specific (in the range  from  1
              to 256 inclusive).

              xerror[,NUM][,error]  -  [ATA  only] prints the Extended Comprehensive SMART error log
              (General Purpose Log address 0x03).  Unlike the Summary SMART error log (see  '-l  er‐
              ror' above), it provides sufficient space to log the contents of the 48-bit LBA regis‐
              ter set introduced with ATA-6.  It also supports logs with more than one sector.  Each
              sector  holds  up  to  4 log entries.  The actual number of log sectors is vendor spe‐
              cific.

              Only the 8 most recent error log entries are printed by default.  This number  can  be
              changed by the optional parameter NUM.

              If  ',error'  is  appended  and the Extended Comprehensive SMART error log is not sup‐
              ported, the Summary SMART self-test log is printed.

              Please note that recent drives may report errors only in  the  Extended  Comprehensive
              SMART  error log.  The Summary SMART error log may be reported as supported but is al‐
              ways empty then.

              selftest - [ATA] prints the SMART self-test log.  The disk maintains a  self-test  log
              showing  the  results  of  the  self tests, which can be run using the '-t' option de‐
              scribed below.  For each of the most recent twenty-one self-tests, the log  shows  the
              type  of  test  (short  or  extended, off-line or captive) and the final status of the
              test.  If the test did not complete successfully, then the percentage of the test  re‐
              maining  is  shown.   The time at which the test took place, measured in hours of disk
              lifetime, is also printed.  [Note: this time stamp wraps after  2^16  hours,  or  2730
              days  and  16  hours,  or  about 7.5 years.]  If any errors were detected, the Logical
              Block Address (LBA) of the first error is printed in decimal notation.

              selftest - [SCSI] the self-test log for a SCSI device has a slightly different  format
              than  for  an ATA device.  For each of the most recent twenty self-tests, it shows the
              type of test and the status (final or in progress) of the test.   SCSI  standards  use
              the terms "foreground" and "background" (rather than ATA's corresponding "captive" and
              "off-line") and "short" and "long" (rather than ATA's corresponding "short"  and  "ex‐
              tended")  to  describe the type of the test.  The printed segment number is only rele‐
              vant when a test fails in the third or later test segment.   It  identifies  the  test
              that  failed  and  consists of either the number of the segment that failed during the
              test, or the number of the test that failed and the number of the segment in which the
              test  was  run,  using  a vendor-specific method of putting both numbers into a single
              byte.  The Logical Block Address (LBA) of the first error is  printed  in  hexadecimal
              notation.  If provided, the SCSI Sense Key (SK), Additional Sense Code (ASC) and Addi‐
              tional Sense Code Qualifier (ASCQ) are also printed.  The self tests can be run  using
              the '-t' option described below (using the ATA test terminology).

              xselftest[,NUM][,selftest]  - [ATA only] prints the Extended SMART self-test log (Gen‐
              eral Purpose Log address 0x07).  Unlike the SMART self-test  log  (see  '-l  selftest'
              above),  it supports 48-bit LBA and logs with more than one sector.  Each sector holds
              up to 19 log entries.  The actual number of log sectors is vendor specific.

              Only the 25 most recent log entries are  printed  by  default.   This  number  can  be
              changed by the optional parameter NUM.

              If  ',selftest' is appended and the Extended SMART self-test log is not supported, the
              old SMART self-test log is printed.

              selective - [ATA only] Please see the '-t select' option below for  a  description  of
              selective  self-tests.   The selective self-test log shows the start/end Logical Block
              Addresses (LBA) of each of the five test spans, and their current test status.  If the
              span  is  being tested or the remainder of the disk is being read-scanned, the current
              65536-sector block of LBAs being tested is also displayed.   The  selective  self-test
              log  also  shows if a read-scan of the remainder of the disk will be carried out after
              the selective self-test has completed (see '-t afterselect' option) and the time delay
              before restarting this read-scan if it is interrupted (see '-t pending' option).

              directory[,gs] - [ATA only] if the device supports the General Purpose Logging feature
              set (ATA-6 and above) then this prints the Log Directory (the log at address 0).   The
              Log  Directory  shows what logs are available and their length in sectors (512 bytes).
              The contents of the logs at address 1 [Summary SMART  error  log]  and  at  address  6
              [SMART self-test log] may be printed using the previously-described error and selftest
              arguments to this option.  If your version of smartctl supports 48-bit  ATA  commands,
              both  the  General Purpose Log (GPL) and SMART Log (SL) directories are printed in one
              combined table.  The output can be restricted to the GPL directory or SL directory  by
              '-l directory,q' or '-l directory,s' respectively.

              background  -  [SCSI only] the background scan results log outputs information derived
              from Background Media Scans (BMS) done after power up and/or periodically (e.g.  every
              24  hours)  on recent SCSI disks.  If supported, the BMS status is output first, indi‐
              cating whether a background scan is currently underway (and if so a progress  percent‐
              age),  the amount of time the disk has been powered up and the number of scans already
              completed.  Then there is a header and a line for each background scan "event".  These
              will  typically  be  either  recovered or unrecoverable errors.  That latter group may
              need some attention.  There is a description of the background scan mechanism in  sec‐
              tion 4.18 of SBC-3 revision 6 (see www.t10.org ).

              scttemp,  scttempsts, scttemphist - [ATA only] prints the disk temperature information
              provided by the SMART Command  Transport  (SCT)  commands.   The  option  'scttempsts'
              prints  current temperature and temperature ranges returned by the SCT Status command,
              'scttemphist' prints temperature limits and the temperature history table returned  by
              the  SCT  Data  Table  command, and 'scttemp' prints both.  The temperature values are
              preserved across power cycles.  The logging interval can be configured  with  the  '-l
              scttempint,N[,p]' option, see below.  The SCT commands were introduced in ATA8-ACS and
              were also supported by many ATA-7 disks.

              scttempint,N[,p] - [ATA only] clears the SCT temperature history table  and  sets  the
              time interval for temperature logging to N minutes.  If ',p' is specified, the setting
              is preserved across power cycles.  Otherwise, the setting is volatile and will be  re‐
              verted  to the last non-volatile setting by the next hard reset.  The default interval
              is vendor specific, typical values are 1, 2, or 5 minutes.

              scterc[,READTIME,WRITETIME] - [ATA only] prints values and descriptions of the SCT Er‐
              ror Recovery Control settings.  These are equivalent to TLER (as used by Western Digi‐
              tal), CCTL (as used by Samsung and Hitachi/HGST) and ERC (as used by Seagate).   READ‐
              TIME and WRITETIME arguments (deciseconds) set the specified values.  Values of 0 dis‐
              able the feature, other values less than 65 are probably not supported.  For RAID con‐
              figurations, this is typically set to 70,70 deciseconds.

              devstat[,PAGE]  -  [ATA only] prints values and descriptions of the ATA Device Statis‐
              tics log pages (General Purpose Log address 0x04).  If no PAGE  number  is  specified,
              entries  from  all  supported  pages are printed.  If PAGE 0 is specified, the list of
              supported pages is printed.  Device Statistics was introduced in  ACS-2  and  is  only
              supported by some recent devices.

              defects[,NUM]  -  [ATA  only] prints LBA and hours values from the ATA Pending Defects
              log (General Purpose Log address 0x0c).  Only the 31 entries from first log  page  are
              printed  by  default.   This number can be changed by the optional parameter NUM.  The
              size of the log and the order of the entries are vendor specific.  The Pending Defects
              log was introduced in ACS-4 Revision 01 (Mar 2014).

              sataphy[,reset]  -  [SATA  only]  prints values and descriptions of the SATA Phy Event
              Counters (General Purpose Log address 0x11).  If '-l sataphy,reset' is specified,  all
              counters  are  reset  after reading the values.  This also works for SATA devices with
              Packet interface like CD/DVD drives.

              sasphy[,reset] - [SAS (SCSI) only] prints values and descriptions  of  the  SAS  (SSP)
              Protocol  Specific  log  page (log page 0x18).  If '-l sasphy,reset' is specified, all
              counters are reset after reading the values.

              gplog,ADDR[,FIRST[-LAST|+SIZE]] - [ATA only] prints a hex dump of any  log  accessible
              via  General  Purpose  Logging (GPL) feature.  The log address ADDR is the hex address
              listed in the log directory (see '-l directory' above).   The  range  of  log  sectors
              (pages)  can  be specified by decimal values FIRST-LAST or FIRST+SIZE.  FIRST defaults
              to 0, SIZE defaults to 1.  LAST can be set to 'max' to specify the last  page  of  the
              log.

              smartlog,ADDR[,FIRST[-LAST|+SIZE]]  - [ATA only] prints a hex dump of any log accessi‐
              ble via SMART Read Log command.  See '-l gplog,...' above for parameter syntax.

              For example, all these commands:
                smartctl -l gplog,0x80,10-15 /dev/sda
                smartctl -l gplog,0x80,10+6 /dev/sda
                smartctl -l smartlog,0x80,10-15 /dev/sda
              print pages 10–15 of log 0x80 (first host vendor specific log).

              The hex dump format is compatible with the 'xxd -r' command.  This command:
                smartctl -l gplog,0x11 /dev/sda | grep ^0 | xxd -r >log.bin
              writes a binary representation of the one sector log 0x11 (SATA Phy Event Counters) to
              file log.bin.

              nvmelog,PAGE,SIZE  -  [NVMe  only]  prints a hex dump of the first SIZE bytes from the
              NVMe log with identifier PAGE.  PAGE is a hexadecimal number in the range from 0x1  to
              0xff.   SIZE  is a hexadecimal number in the range from 0x4 to 0x4000 (16 KiB).  WARN‐‐
              ING: Do not specify the identifier of an unknown log page.  Reading  a  log  page  may
              have undesirable side effects.

              ssd  - [ATA] prints the Solid State Device Statistics log page.  This has the same ef‐
              fect as '-l devstat,7', see above.

              ssd - [SCSI] prints the Solid State Media  percentage  used  endurance  indicator.   A
              value  of 0 indicates as new condition while 100 indicates the device is at the end of
              its lifetime as projected by the manufacturer.  The value may reach 255.

       -v ID,FORMAT[:BYTEORDER][,NAME], --vendorattribute=ID,FORMAT...
              [ATA only] Sets a vendor-specific raw value print FORMAT, an optional BYTEORDER and an
              optional NAME for Attribute ID.  This option may be used multiple times.

              The  Attribute  ID  can be in the range 1 to 255.  If 'N' is specified as ID, the set‐
              tings for all Attributes are changed.

              The optional BYTEORDER consists of 1 to 8 characters from the set  '012345rvwz'.   The
              characters  '0'  to  '5' select the byte 0 to 5 from the 48-bit raw value, 'r' selects
              the reserved byte of the attribute data block, 'v' selects the normalized  value,  'w'
              selects  the  worst  value  and  'z'  inserts  a  zero byte.  The default BYTEORDER is
              '543210' for all 48-bit formats, 'r543210' for the 54-bit formats, and '543210wv'  for
              the  64-bit  formats.  For example, '-v 5,raw48:012345' prints the raw value of attri‐
              bute 5 with big endian instead of little endian byte ordering.

              The NAME is a string of letters, digits and underscore.  Its length should not  exceed
              23 characters.  The '-P showall' option reports an error if this is the case.

              -v help - Prints (to STDOUT) a list of all valid arguments to this option, then exits.

              Valid arguments for FORMAT are:

              raw8 - Print the Raw value as six 8-bit unsigned base-10 integers.  This may be useful
              for decoding the meaning of the Raw value.

              raw16 - Print the Raw value as three 16-bit unsigned base-10 integers.   This  may  be
              useful for decoding the meaning of the Raw value.

              raw48 - Print the Raw value as a 48-bit unsigned base-10 integer.  This is the default
              for most attributes.

              hex48 - Print the Raw value as a 12 digit hexadecimal number.  This may be useful  for
              decoding the meaning of the Raw value.

              raw56  -  Print the Raw value as a 54-bit unsigned base-10 integer.  This includes the
              reserved byte which follows the 48-bit raw value.

              hex56 - Print the Raw value as a 14 digit hexadecimal number.  This includes  the  re‐
              served byte which follows the 48-bit raw value.

              raw64  -  Print the Raw value as a 64-bit unsigned base-10 integer.  This includes two
              bytes from the normalized and worst attribute value.  This raw format is used by  some
              SSD devices with Indilinx controller.

              hex64 - Print the Raw value as a 16 digit hexadecimal number.  This includes two bytes
              from the normalized and worst attribute value.  This raw format is used  by  some  SSD
              devices with Indilinx controller.

              min2hour - Raw Attribute is power-on time in minutes.  Its raw value will be displayed
              in the form "Xh+Ym".  Here X is hours, and Y is minutes in the range  0–59  inclusive.
              Y is always printed with two digits, for example "06" or "31" or "00".

              sec2hour - Raw Attribute is power-on time in seconds.  Its raw value will be displayed
              in the form "Xh+Ym+Zs".  Here X is hours, Y is minutes in the  range  0–59  inclusive,
              and  Z  is  seconds  in the range 0–59 inclusive.  Y and Z are always printed with two
              digits, for example "06" or "31" or "00".

              halfmin2hour - Raw Attribute is power-on time, measured in units of 30 seconds.   This
              format  is  used  by  some Samsung disks.  Its raw value will be displayed in the form
              "Xh+Ym".  Here X is hours, and Y is minutes in the range 0–59 inclusive.  Y is  always
              printed with two digits, for example "06" or "31" or "00".

              msec24hour32 - Raw Attribute is power-on time measured in 32-bit hours and 24-bit mil‐
              liseconds since last hour update.  It will be  displayed  in  the  form  "Xh+Ym+Z.Ms".
              Here X is hours, Y is minutes, Z is seconds and M is milliseconds.

              tempminmax  -  Raw  Attribute  is the disk temperature in Celsius.  Info about Min/Max
              temperature is printed if available.  This is the default for Attributes 190 and  194.
              The  recording  interval  (lifetime, last power cycle, last soft reset) of the min/max
              values is device specific.

              temp10x - Raw Attribute is ten times the disk temperature in Celsius.

              raw16(raw16) - Print the raw attribute as a 16-bit value and two optional 16-bit  val‐
              ues if these words are nonzero.  This is the default for Attributes 5 and 196.

              raw16(avg16)  - Raw attribute is spin-up time.  It is printed as a 16-bit value and an
              optional "Average" 16-bit value if the word is nonzero.  This is the default  for  At‐
              tribute 3.

              raw24(raw8)  - Print the raw attribute as a 24-bit value and three optional 8-bit val‐
              ues if these bytes are nonzero.  This is the default for Attribute 9.

              raw24/raw24 - Raw Attribute contains two 24-bit values.  The first is  the  number  of
              load cycles.  The second is the number of unload cycles.  The difference between these
              two values is the number of times that the drive was unexpectedly  powered  off  (also
              called an emergency unload).  As a rule of thumb, the mechanical stress created by one
              emergency unload is equivalent to that created by one hundred normal unloads.

              raw24/raw32 - Raw attribute is an error rate which consists of a  24-bit  error  count
              and a 32-bit total count.

              The following old arguments to '-v' are also still valid:

              9,minutes - same as: 9,min2hour,Power_On_Minutes.

              9,seconds - same as: 9,sec2hour,Power_On_Seconds.

              9,halfminutes - same as: 9,halfmin2hour,Power_On_Half_Minutes.

              9,temp - same as: 9,tempminmax,Temperature_Celsius.

              192,emergencyretractcyclect - same as: 192,raw48,Emerg_Retract_Cycle_Ct

              193,loadunload - same as: 193,raw24/raw24.

              194,10xCelsius - same as: 194,temp10x,Temperature_Celsius_x10.

              194,unknown - same as: 194,raw48,Unknown_Attribute.

              197,increasing  - same as: 197,raw48,Total_Pending_Sectors.  Also means that Attribute
              number 197 (Current Pending Sector Count) is not reset if  uncorrectable  sectors  are
              reallocated (see smartd.conf(5) man page).

              198,increasing  -  same as: 198,raw48,Total_Offl_Uncorrectabl.  Also means that Attri‐
              bute number 198 (Offline Uncorrectable Sector Count) is  not  reset  if  uncorrectable
              sectors are reallocated (see smartd.conf(5) man page).

              198,offlinescanuncsectorct - same as: 198,raw48,Offline_Scan_UNC_SectCt.

              200,writeerrorcount - same as: 200,raw48,Write_Error_Count.

              201,detectedtacount - same as: 201,raw48,Detected_TA_Count.

              220,temp - same as: 220,tempminmax,Temperature_Celsius.

       -F TYPE, --firmwarebug=TYPE
              [ATA  only]  Modifies the behavior of smartctl to compensate for some known and under‐
              stood device firmware or driver bug.  This option may be  used  multiple  times.   The
              valid arguments are:

              none  - Assume that the device firmware obeys the ATA specifications.  This is the de‐
              fault, unless the device has presets for '-F' in the drive database.  Using  this  op‐
              tion on the command line will override any preset values.

              nologdir  -  Suppresses  read  attempts of SMART or GP Log Directory.  Support for all
              standard logs is assumed without an actual check.  Some Intel SSDs may freeze  if  log
              address 0 is read.

              samsung  -  In  some Samsung disks (example: model SV4012H Firmware Version: RM100-08)
              some of the two- and four-byte quantities in  the  SMART  data  structures  are  byte-
              swapped  (relative  to the ATA specification).  Enabling this option tells smartctl to
              evaluate these quantities in byte-reversed order.  Some signs  that  your  disk  needs
              this option are (1) no self-test log printed, even though you have run self-tests; (2)
              very large numbers of ATA errors reported in the ATA error log; (3) strange and impos‐
              sible values for the ATA error log timestamps.

              samsung2  -  In  some Samsung disks the number of ATA errors reported is byte swapped.
              Enabling this option tells smartctl to evaluate this quantity in byte-reversed  order.
              An  indication  that  your Samsung disk needs this option is that the self-test log is
              printed correctly, but there are a very large number of errors in the SMART error log.
              This  is  because  the  error  count  is  byte  swapped.  Thus a disk with five errors
              (0x0005) will appear to have 20480 errors (0x5000).

              samsung3 - Some Samsung disks (at least SP2514N with Firmware VF100-37) report a self-
              test  still  in  progress  with 0% remaining when the test was already completed.  En‐
              abling this option modifies the output of the self-test execution status (see  options
              '-c' or '-a' above) accordingly.

              xerrorlba  -  Fixes LBA byte ordering in Extended Comprehensive SMART error log.  Some
              disks use little endian byte ordering instead of ATA register ordering to specify  the
              LBA addresses in the log entries.

              swapid - Fixes byte swapped ATA identify strings (device name, serial number, firmware
              version) returned by some buggy device drivers.

       -P TYPE, --presets=TYPE
              [ATA only] Specifies whether smartctl should use any preset options that are available
              for this drive.  By default, if the drive is recognized in the smartmontools database,
              then the presets are used.

              The argument show will show any preset options for your drive and the argument showall
              will  show all known drives in the smartmontools database, along with their preset op‐
              tions.  If there are no presets for your drive and you think there should be (for  ex‐
              ample,  a  -v  or  -F option is needed to get smartctl to display correct values) then
              please contact the smartmontools developers so that this information can be  added  to
              the smartmontools database.  Contact information is at the end of this man page.

              The valid arguments to this option are:

              use  -  if a drive is recognized, then use the stored presets for it.  This is the de‐
              fault.  Note that presets will NOT override additional Attribute  interpretation  ('-v
              N,something') command-line options or explicit '-F' command-line options..

              ignore - do not use presets.

              show  -  show if the drive is recognized in the database, and if so, its presets, then
              exit.

              showall - list all recognized drives, and the presets that  are  set  for  them,  then
              exit.  This also checks the drive database regular expressions and settings for syntax
              errors.

              The '-P showall' option takes up to two optional arguments to match a  specific  drive
              type and firmware version.  The command:
                smartctl -P showall
              lists all entries, the command:
                smartctl -P showall 'MODEL'
              lists all entries matching MODEL, and the command:
                smartctl -P showall 'MODEL' 'FIRMWARE'
              lists all entries for this MODEL and a specific FIRMWARE version.

       -B [+]FILE, --drivedb=[+]FILE
              [ATA  only] Read the drive database from FILE.  The new database replaces the built in
              database by default.  If '+' is specified, then the new entries prepend the  built  in
              entries.

              Optional  entries  are  read  from the file /etc/smart_drivedb.h if this option is not
              specified.

              If /var/lib/smartmontools/drivedb/drivedb.h is present, the contents of this  file  is
              used instead of the built in table.

              Run  /usr/sbin/update-smart-drivedb  to  update  this  file from the smartmontools SVN
              repository.

              The database files use the same C/C++ syntax that is used to initialize the  built  in
              database array.  C/C++ style comments are allowed.  Example:

                /* Full entry: */
                {
                  "Model family",    // Info about model family/series.
                  "MODEL1.*REGEX",   // Regular expression to match model of device.
                  "VERSION.*REGEX",  // Regular expression to match firmware version(s).
                  "Some warning",    // Warning message.
                  "-v 9,minutes"     // String of preset -v and -F options.
                },
                /* Minimal entry: */
                {
                  "",                // No model family/series info.
                  "MODEL2.*REGEX",   // Regular expression to match model of device.
                  "",                // All firmware versions.
                  "",                // No warning.
                  ""                 // No options preset.
                },
                /* USB ID entry: */
                {
                  "USB: Device; Bridge", // Info about USB device and bridge name.
                  "0x1234:0xabcd",   // Regular expression to match vendor:product ID.
                  "0x0101",          // Regular expression to match bcdDevice.
                  "",                // Not used.
                  "-d sat"           // String with device type option.
                },
                /* ... */


       SMART RUN/ABORT OFFLINE TEST AND self-test OPTIONS:

       -t TEST, --test=TEST
              Executes  TEST  immediately.  The '-C' option can be used in conjunction with this op‐
              tion to run the short or long (and also for  ATA  devices,  selective  or  conveyance)
              self-tests  in  captive mode (known as "foreground mode" for SCSI devices).  Note that
              only one test type can be run at a time, so only one test type should be specified per
              command line.  Note also that if a computer is shutdown or power cycled during a self-
              test, no harm should result.  The self-test will either be aborted or will resume  au‐
              tomatically.

              All '-t TEST' commands can be given during normal system operation unless captive mode
              ('-C' option) is used.  A running self-test can, however, degrade performance  of  the
              drive.   Frequent  I/O  requests  from the operating system increase the duration of a
              test.  These impacts may vary from device to device.

              If a test failure occurs then the device may discontinue the testing  and  report  the
              result immediately.

              [ATA] Note that the ATA command SMART EXECUTE OFF-LINE IMMEDIATE (the command to start
              a test) was declared obsolete in ATA ACS-4 Revision 10 (Nov 2015).

              The valid arguments to this option are:

              offline - [ATA] runs SMART Immediate Offline Test.  This immediately starts  the  test
              described  above.   This command can be given during normal system operation.  The ef‐
              fects of this test are visible only in that it updates the SMART Attribute values, and
              if  errors are found they will appear in the SMART error log, visible with the '-l er‐
              ror' option.

              If the '-c' option to smartctl shows that the device has the "Suspend Offline  collec‐
              tion  upon  new  command"  capability then you can track the progress of the Immediate
              Offline test using the '-c' option to smartctl.  If the '-c' option show that the  de‐
              vice has the "Abort Offline collection upon new command" capability then most commands
              will abort the Immediate Offline Test, so you should not try to track the progress  of
              the test with '-c', as it will abort the test.

              offline  - [SCSI] runs the default self test in foreground.  No entry is placed in the
              self test log.

              short - [ATA] runs SMART Short Self Test (usually under ten  minutes).   This  command
              can be given during normal system operation (unless run in captive mode - see the '-C'
              option below).  This is a test in a different category than the immediate or automatic
              offline  tests.   The  "Self" tests check the electrical and mechanical performance as
              well as the read performance of the disk.  Their results are reported in the Self Test
              Error  Log,  readable  with  the  '-l  selftest'  option.  Note that on some disks the
              progress of the self-test can be monitored by watching this log during the  self-test;
              with other disks use the '-c' option to monitor progress.

              short - [SCSI] runs the "Background short" self-test.

              long  -  [ATA] runs SMART Extended Self Test (tens of minutes to several hours).  This
              is a longer and more thorough version of the Short Self Test  described  above.   Note
              that  this  command can be given during normal system operation (unless run in captive
              mode - see the '-C' option below).

              long - [SCSI] runs the "Background long" self-test.

              conveyance - [ATA only] runs a SMART Conveyance Self Test (minutes).   This  self-test
              routine  is  intended  to  identify damage incurred during transporting of the device.
              This self-test routine should take on the order of minutes  to  complete.   Note  that
              this command can be given during normal system operation (unless run in captive mode -
              see the '-C' option below).

              select,N-M, select,N+SIZE - [ATA only] runs a SMART Selective Self  Test,  to  test  a
              range of disk Logical Block Addresses (LBAs), rather than the entire disk.  Each range
              of LBAs that is checked is called a "span" and is specified by a starting LBA (N)  and
              an  ending LBA (M) with N less than or equal to M.  The range can also be specified as
              N+SIZE.  A span at the end of a disk can be specified by N-max.

              For example the commands:
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,10+11 /dev/sda
              both runs a self test on one span consisting of LBAs ten to twenty  (inclusive).   The
              command:
                smartctl -t select,100000000-max /dev/sda
              run  a self test from LBA 100000000 up to the end of the disk.  The '-t' option can be
              given up to five times, to test up to five spans.  For example the command:
                smartctl -t select,0-100 -t select,1000-2000 /dev/sda
              runs a self test on two spans.  The first span consists of 101  LBAs  and  the  second
              span  consists of 1001 LBAs.  Note that the spans can overlap partially or completely,
              for example:
                smartctl -t select,0-10 -t select,5-15 -t select,10-20 /dev/sda
              The results of the selective self-test can be obtained  (both  during  and  after  the
              test) by printing the SMART self-test log, using the '-l selftest' option to smartctl.

              Selective  self tests are particularly useful as disk capacities increase: an extended
              self test (smartctl -t long) can take several hours.  Selective self-tests are helpful
              if (based on SYSLOG error messages, previous failed self-tests, or SMART error log en‐
              tries) you suspect that a disk is having problems at a  particular  range  of  Logical
              Block Addresses (LBAs).

              Selective self-tests can be run during normal system operation (unless done in captive
              mode - see the '-C' option below).

              The following variants of the selective self-test  command  use  spans  based  on  the
              ranges from past tests already stored on the disk:

              select,redo[+SIZE] - [ATA only] redo the last SMART Selective Self Test using the same
              LBA range.  The starting LBA is identical to the LBA used by last test, same for  end‐
              ing LBA unless a new span size is specified by optional +SIZE argument.

              For example the commands:
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,redo /dev/sda
                smartctl -t select,redo+20 /dev/sda
              have the same effect as:
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,10-29 /dev/sda

              select,next[+SIZE]  -  [ATA  only]  runs  a SMART Selective Self Test on the LBA range
              which follows the range of the last test.  The starting LBA is set to (ending LBA  +1)
              of the last test.  A new span size may be specified by the optional +SIZE argument.

              For example the commands:
                smartctl -t select,0-999 /dev/sda
                smartctl -t select,next /dev/sda
                smartctl -t select,next+2000 /dev/sda
              have the same effect as:
                smartctl -t select,0-999 /dev/sda
                smartctl -t select,1000-1999 /dev/sda
                smartctl -t select,2000-3999 /dev/sda

              If  the  last  test  ended at the last LBA of the disk, the new range starts at LBA 0.
              The span size of the last span of a disk is adjusted such that  the  total  number  of
              spans to check the full disk will not be changed by future uses of '-t select,next'.

              select,cont[+SIZE]  - [ATA only] performs a 'redo' (above) if the self test status re‐
              ports that the last test was aborted by the host.  Otherwise it run the 'next' (above)
              test.

              afterselect,on  -  [ATA only] perform an offline read scan after a Selective self-test
              has completed.  This option must be used together with one or more of  the  select,N-M
              options  above.   If the LBAs that have been specified in the Selective self-test pass
              the test with no errors found, then read scan the remainder of the disk.  If  the  de‐
              vice  is powered-cycled while this read scan is in progress, the read scan will be au‐
              tomatically resumed after a time specified by the  pending  timer  (see  below).   The
              value of this option is preserved between selective self-tests.

              afterselect,off - [ATA only] do not read scan the remainder of the disk after a Selec‐
              tive self-test has completed.  This option must be use together with one  or  more  of
              the select,N-M options above.  The value of this option is preserved between selective
              self-tests.

              pending,N - [ATA only] set the pending offline read scan timer to N minutes.   Here  N
              is  an  integer  in the range from 0 to 65535 inclusive.  If the device is powered off
              during a read scan after a Selective self-test, then resume the test  automatically  N
              minutes  after power-up.  This option must be use together with one or more of the select,N-M options above.  The value of this option is preserved between selective self-
              tests.

              vendor,N  -  [ATA  only]  issues the ATA command SMART EXECUTE OFF-LINE IMMEDIATE with
              subcommand N in LBA LOW register.  The subcommand is specified as a hex value  in  the
              range  0x00 to 0xff.  Subcommands 0x40–0x7e and 0x90–0xff are reserved for vendor spe‐
              cific use, see table 61 of T13/1699-D Revision 6a (ATA8-ACS).  Note that  the  subcom‐
              mands  0x00–0x04,  0x7f, 0x81–0x84 are supported by other smartctl options (e.g. 0x01:
              '-t short', 0x7f: '-X', 0x82: '-C -t long').

              WARNING: Only run subcommands documented by the vendor of the device.

              Example for some Intel SSDs only: The subcommand 0x40 ('-t  vendor,0x40')  clears  the
              timed  workload related SMART attributes (226, 227, 228).  Note that the raw values of
              these attributes are held at 65535 (0xffff) until the workload timer reaches  60  min‐
              utes.

              force  -  start  new  self-test even if another test is already running.  By default a
              running self-test will not be interrupted to begin another test.

       -C, --captive
              [ATA] Runs self-tests in captive mode.  This has no effect with '-t offline' or if the
              '-t' option is not used.

              WARNING:  Tests run in captive mode may busy out the drive for the length of the test.
              Only run captive tests on drives without any mounted partitions!

              [SCSI] Runs the self-test in "Foreground" mode.

       -X, --abort
              Aborts non-captive SMART Self Tests.  Note that this command will  abort  the  Offline
              Immediate  Test  routine  only if your disk has the "Abort Offline collection upon new
              command" capability.


ATA, SCSI command sets and SAT
       In the past there has been a clear distinction between storage devices that used the ATA  and
       SCSI command sets.  This distinction was often reflected in their device naming and hardware.
       Now various SCSI transports (e.g. SAS, FC and iSCSI) can  interconnect  to  both  SCSI  disks
       (e.g. FC and SAS) and ATA disks (especially SATA).  USB and IEEE 1394 storage devices use the
       SCSI command set externally but almost always contain ATA or  SATA  disks  (or  flash).   The
       storage  subsystems  in some operating systems have started to remove the distinction between
       ATA and SCSI in their device naming policies.

       99% of operations that an OS performs on a disk involve the SCSI INQUIRY, READ CAPACITY, READ
       and WRITE commands, or their ATA equivalents.  Since the SCSI commands are slightly more gen‐
       eral than their ATA equivalents, many OSes are generating  SCSI  commands  (mainly  READ  and
       WRITE)  and letting a lower level translate them to their ATA equivalents as the need arises.
       An important note here is that "lower level" may be in external equipment and  hence  outside
       the control of an OS.

       SCSI  to  ATA  Translation (SAT) is a standard (ANSI INCITS 431-2007) that specifies how this
       translation is done.  For the other 1% of operations that an OS performs on a disk, SAT  pro‐
       vides  two  options.  First is an optional ATA PASS-THROUGH SCSI command (there are two vari‐
       ants).  The second is a translation from the closest SCSI command.  Most current interest  is
       in the "pass-through" option.

       The  relevance to smartmontools (and hence smartctl) is that its interactions with disks fall
       solidly into the "1%" category.  So even if the OS can happily treat (and  name)  a  disk  as
       "SCSI",  smartmontools  needs  to detect the native command set and act accordingly.  As more
       storage manufacturers (including external SATA drives) comply with SAT, smartmontools is able
       to  automatically  distinguish  the  native command set of the device.  In some cases the '-d
       sat' option is needed on the command line.

       There are also virtual disks which typically have no useful information to convey  to  smart‐
       montools, but could conceivably in the future.  An example of a virtual disk is the OS's view
       of a RAID 1 box.  There are most likely two SATA disks inside a RAID 1 box.  Addressing those
       SATA disks from a distant OS is a challenge for smartmontools.  Another approach is running a
       tool like smartmontools inside the RAID 1 box (e.g.  a Network Attached  Storage  (NAS)  box)
       and fetching the logs via a browser.


EXAMPLES
       smartctl -a /dev/sda
       Print a large amount of SMART information for drive /dev/sda.

       smartctl -s off /dev/sdd
       Disable SMART monitoring and data log collection on drive /dev/sdd.

       smartctl --smart=on --offlineauto=on --saveauto=on /dev/sda
       Enable SMART on drive /dev/sda, enable automatic offline testing every four hours, and enable
       autosaving of SMART Attributes.  This is a good start-up line for your system's  init  files.
       You can issue this command on a running system.

       smartctl -t long /dev/sdc
       Begin  an extended self-test of drive /dev/sdc.  You can issue this command on a running sys‐
       tem.  The results can be seen in the self-test log visible with the '-l selftest' option  af‐
       ter it has completed.

       smartctl -s on -t offline /dev/sda
       Enable SMART on the disk, and begin an immediate offline test of drive /dev/sda.  You can is‐
       sue this command on a running system.  The results are only used  to  update  the  SMART  At‐
       tributes,  visible  with the '-A' option.  If any device errors occur, they are logged to the
       SMART error log, which can be seen with the '-l error' option.

       smartctl -A -v 9,minutes /dev/sda
       Shows the vendor Attributes, when the disk stores its power-on  time  internally  in  minutes
       rather than hours.

       smartctl -q errorsonly -H -l selftest /dev/sda
       Produces  output  only  if  the device returns failing SMART status, or if some of the logged
       self-tests ended with errors.

       smartctl -q silent -a /dev/sda
       Examine all SMART data for device /dev/sda, but produce no printed output.  You must use  the
       exit  status  (the  $?   shell  variable) to learn if any Attributes are out of bound, if the
       SMART status is failing, if there are errors recorded in the self-test log, or if  there  are
       errors recorded in the disk error log.

       smartctl -a -d 3ware,0 /dev/twl0
       Examine  all SMART data for the first SATA (not SAS) disk connected to a 3ware RAID 9750 con‐
       troller card.

       smartctl -t long -d areca,4 /dev/sg2
       Start a long self-test on the fourth SATA disk connected to  an  Areca  RAID  controller  ad‐
       dressed by /dev/sg2.

       smartctl -a -d hpt,1/3 /dev/sda (under Linux)
       smartctl -a -d hpt,1/3 /dev/hptrr (under FreeBSD)
       Examine  all  SMART  data  for the (S)ATA disk directly connected to the third channel of the
       first HighPoint RocketRAID controller card.

       smartctl -t short -d hpt,1/1/2 /dev/sda (under Linux)
       smartctl -t short -d hpt,1/1/2 /dev/hptrr (under FreeBSD)
       Start a short self-test on the (S)ATA disk connected to second pmport on the first channel of
       the first HighPoint RocketRAID controller card.

       smartctl -t select,10-100 -t select,30-300 -t afterselect,on -t pending,45 /dev/sda
       Run  a  selective  self-test on LBAs 10 to 100 and 30 to 300.  After the these LBAs have been
       tested, read-scan the remainder of the disk.  If the disk is power-cycled  during  the  read-
       scan, resume the scan 45 minutes after power to the device is restored.

       smartctl -a -d cciss,0 /dev/cciss/c0d0
       Examine all SMART data for the first SCSI disk connected to a cciss RAID controller card.


EXIT STATUS
       The  exit  statuses  of smartctl are defined by a bitmask.  If all is well with the disk, the
       exit status (return value) of smartctl is 0 (all bits turned off).  If a problem  occurs,  or
       an error, potential error, or fault is detected, then a non-zero status is returned.  In this
       case, the eight different bits in the exit status have the following meanings for ATA  disks;
       some of these values may also be returned for SCSI disks.

       Bit 0: Command line did not parse.

       Bit 1: Device  open  failed, device did not return an IDENTIFY DEVICE structure, or device is
              in a low-power mode (see '-n' option above).

       Bit 2: Some SMART or other ATA command to the disk failed, or there was a checksum error in a
              SMART data structure (see '-b' option above).

       Bit 3: SMART status check returned "DISK FAILING".

       Bit 4: We found prefail Attributes <= threshold.

       Bit 5: SMART  status  check  returned "DISK OK" but we found that some (usage or prefail) At‐
              tributes have been <= threshold at some time in the past.

       Bit 6: The device error log contains records of errors.

       Bit 7: The device self-test log contains records of errors.   [ATA  only]  Failed  self-tests
              outdated by a newer successful extended self-test are ignored.

       To  test within the shell for whether or not the different bits are turned on or off, you can
       use the following type of construction (which should work with any POSIX compatible shell):
       smartstat=$(($? & 8))
       This looks at only at bit 3 of the exit status $?  (since 8=2^3).  The shell variable $smart‐
       stat will be nonzero if SMART status check returned "disk failing" and zero otherwise.

       This shell script prints all status bits:
       val=$?; mask=1
       for i in 0 1 2 3 4 5 6 7; do
         echo "Bit $i: $(((val & mask) && 1))"
         mask=$((mask << 1))
       done


FILES
       /usr/sbin/smartctl
              full path of this executable.

       /var/lib/smartmontools/drivedb/drivedb.h
              drive database (see '-B' option).

       /etc/smart_drivedb.h
              optional local drive database (see '-B' option).


AUTHORS
       Bruce Allen (project initiator),
       Christian Franke (project manager, Windows port and all sort of things),
       Douglas Gilbert (SCSI subsystem),
       Volker Kuhlmann (moderator of support and database mailing list),
       Gabriele Pohl (wiki & development team support),
       Alex Samorukov (FreeBSD port and more, new Trac wiki).

       Many  other  individuals  have made contributions and corrections, see AUTHORS, ChangeLog and
       repository files.

       The first smartmontools code was derived from the  smartsuite  package,  written  by  Michael
       Cornwell and Andre Hedrick.


REPORTING BUGS
       To submit a bug report, create a ticket in smartmontools wiki:
       <https://www.smartmontools.org/>.
       Alternatively send the info to the smartmontools support mailing list:
       <https://listi.jpberlin.de/mailman/listinfo/smartmontools-support>.


SEE ALSO
       smartd(8).
       update-smart-drivedb(8).


REFERENCES
       Please see the following web site for more info: <https://www.smartmontools.org/>

       An  introductory  article  about  smartmontools is Monitoring Hard Disks with SMART, by Bruce
       Allen, Linux Journal, January 2004,  pages  74–77.   See  <https://www.linuxjournal.com/arti‐‐
       cle/6983>.

       If  you  would  like  to understand better how SMART works, and what it does, a good place to
       start is with Sections 4.8 and 6.54 of the first volume of the 'AT Attachment with Packet In‐
       terface-7'  (ATA/ATAPI-7)  specification Revision 4b.  This documents the SMART functionality
       which the smartmontools utilities provide access to.

       The functioning of SMART was originally defined by the SFF-8035i revision 2 and the SFF-8055i
       revision  1.4 specifications.  These are publications of the Small Form Factors (SFF) Commit‐
       tee.

       Links to these and other documents may be found on the Links page of the  smartmontools  Wiki
       at <https://www.smartmontools.org/wiki/Links>.


PACKAGE VERSION
       smartmontools-7.2 2020-12-30 r5155
       $Id: smartctl.8.in 5143 2020-12-21 18:34:31Z chrfranke $



smartmontools-7.2                            2020-12-30                                  SMARTCTL(8)

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