# SG_LOGS - access log pages with SCSI LOG SENSE command - man(8) - [phpMan] [_SG_LOGS_(8)](https://www.chedong.com/phpMan.php/man/SGLOGS/8/markdown) SG3_UTILS [_SG_LOGS_(8)](https://www.chedong.com/phpMan.php/man/SGLOGS/8/markdown) ## NAME sg_logs - access log pages with SCSI LOG SENSE command ## SYNOPSIS **sg_logs **[_--All_] [_--all_] [_--brief_] [_--filter=FL_] [_--hex_] [_--list_] [_--maxlen=LEN_] [_--name_] [_--no_inq_] [_--page=PG_] [_--paramp=PP_] [_--pcb_] [_--ppc_] [_--pdt=DT_] [_--raw_] [_--readonly_] [_--sp_] [_--temperature_] [_--transport_] [_--vendor=VP_] [_--verbose_] _DEVICE_ **sg_logs **[_--brief_] [_--filter=FL_] [_--hex_] _--in=FN_ [_--name_] [_--pdt=DT_] [_--raw_] [_--vendor=VP_] **sg_logs **[_--control=PC_] [_--in=FN_] [_--page=PG_] [_--raw_] [_--reset_] _--select_ [_--sp_] [_--verbose_] _DEVICE_ **sg_logs **[_--enumerate_] [_--filter=FL_] [_--help_] [_--vendor=VP_] [_--version_] **sg_logs **[_-a_] [_-A_] [_-b_] [_-D=DT_] [_-c=PC_] [_-e_] [_-f=FL_] [_-h_] [_-H_] [_-i=FN_] [_-l_] [_-L_] [_-m=LEN_] [_-M=VP_] [_-n_] [_-p=PG_] [_-paramp=PP_] [_-pcb_] [_-ppc_] [_-r_] [_-R_] [_-select_] [_-sp_] [_-t_] [_-T_] [_-v_] [_-V_] [_-?_] [_-x_] _DEVICE_ ## DESCRIPTION This utility sends a SCSI LOG SENSE command to the _DEVICE_ and then outputs the response. The LOG SENSE command is used to fetch log pages which, if known, are decoded by default. When the _--reset_ and/or _--select_ option is given then a SCSI LOG SELECT command is issued to the _DEVICE_. Alternatively one or more log page responses can be in a file read using the _--in=FN_ option; in this case those responses are decoded and the _DEVICE_ argument, if given, is ig‐ nored. In SPC-4 revision 5 a subpage code was introduced to both the LOG SENSE and LOG SELECT com‐ mand. At the same time a page code field was introduced to the to the LOG SELECT command. The log subpage code can range from 0 to 255 (0xff) inclusive. The subpage code value 255 can be thought of as a wildcard. The SYNOPSIS section above is divided into five forms. The first form shows the options that can be used to send a LOG SENSE command to the _DEVICE_ and decode its response. The second form fetches data from a file (named _FN_) and decodes it as if it were a response from a LOG SENSE command. The third form shows the options that can be used to send a LOG SELECT com‐ mand. The fourth form groups various management options. The last form shows the older, dep‐ recated command line interface which is maintained for backward compatibility. ## OPTIONS Arguments to long options are mandatory for short options as well. The options are arranged in alphabetical order based on the long option name. ### -A --All fetch and decode all the log pages and subpages supported by the _DEVICE_. This re‐ quires a two stage process: first the "supported log pages and subpages" log page is fetched, then for each entry in its response, the corresponding log page (or subpage) is fetched and displayed. Note that there are many SCSI devices that do not support LOG SENSE subpages and respond to this option with an illegal request sense key (or ignored the subpage field). ### -a --all outputs all the log pages supported by the _DEVICE_. This requires a two stage process: first the "supported log pages" log page is fetched, then for each entry in its re‐ sponse, the corresponding log page is fetched and displayed. When used twice (e.g. '-aa') all log pages and subpages are fetched. ### -b --brief shorten the amount of output for some log pages. For example the Tape Alert log page only outputs parameters whose flags are set when _--brief_ is given. ### -c --control accepts 0, 1, 2 or 3 for the _PC_ argument: **0 **: current threshold values **1 **: current cumulative values **2 **: default threshold values **3 **: default cumulative values The default value is 1 (i.e. current cumulative values). ### -e --enumerate this option is used to output information held in this utility's internal tables about known log pages including their name, acronym and fields. If given, the _DEVICE_ argu‐ ment is ignored. When given once (e.g. '-e') all known pages are listed, sorted in as‐ cending alphabetical acronym order. When given twice, vendor pages are excluded. When given three times, all known pages are listed, sorted in ascending numeric order listed; when given four times, vendor pages are excluded from the numeric order. The _--filter=FL_ and _--verbose_ options reduce the output of the enumeration. ### -f --filter _FL_ is either a parameter code when _DEVICE_ is given, or a peripheral device type (pdt) (or other) if _--enumerate_ is given. In the parameter code case _FL_ is a value between 0 and 65535 (0xffff) and only the pa‐ rameter section matching that code is output. If the **--hex **option is given the log pa‐ rameter is output in hexadecimal rather than decoding it. If the **--hex **option is used twice then the leading address on each line of hex is removed. If the **--raw **option is given then the log parameter is output in binary. Most log pages contain one or more log parameters. Examples of those that don't follow that convention are those pages that list supported log pages (and subpages). In the _--enumerate_ case, when _FL_ >= zero it is taken as a pdt value and only log pages associated with that pdt plus generic pages listed in SPC are enumerated. If _FL_ is -1 then the filter does nothing which is the same as not giving this option; when _FL_ is -2 then only generic pages listed in SPC are enumerated. If _FL_ is -10 then only generic direct access like (e.g. disk) pages are enumerated. If _FL_ is -11 then only generic tape like pages (e.g. includes ADC) are enumerated. ### -h --help print out the usage message then exit. ### -H --hex The default action is to decode known log page numbers (and subpage numbers) into text. When this option is used once, the response is output in hexadecimal. When used twice, each line of hex has the ASCII equivalent shown to the right. When used three times, the hex has no leading address nor trailing ASCII making it suitable to be placed in a file (or piped). That file might later be used by another invocation using the _--in=FN_ option. ### -i --in This option may be used in two different contexts. One is with the _--select_ to send a LOG SELECT command to the given _DEVICE_; see the LOG SELECT section below. The other context is with no _DEVICE_ argument given in which case the contents of _FN_ are decoded as if it were the response of a LOG SENSE command (i.e. a log page). For decoding the page and subpage numbers are taken from _FN_ while the peripheral device type is either generic (i.e. from SPC) or the value given by _--pdt=DT_. _FN_ is treated as a file name (or '-' for stdin) which contains ASCII hexadecimal or binary representing a log page. The hexadecimal should be arranged as 1 or 2 digits representing a byte each of which is whitespace or comma separated. Anything from and including a hash mark to the end of line is ignored. If the _--raw_ option is also given then _FN_ is treated as binary. ### -l --list lists the names of all logs sense pages supported by this device. This is done by reading the "supported log pages" log page. When used twice (e.g. '-ll') lists the names of all logs sense pages and subpages supported by this device, excluding pages whose subpage number is 0xff (apart from page 0x0,0xff). When used three times then all supported pages and subpages reported by the device are list. So the page/subpage names and not thrie content is shown with this option. There is a list of common log page codes below. ### -m --maxlen sets the "allocation length" field in the LOG SENSE cdb. The is the maximum length in bytes that the response will be. Without this option (or _LEN_ equal to 0) this utility first fetches the 4 byte response then does a second access with the length indicated in the first (4 byte) response. Negative values and 1 for _LEN_ are not accepted. _LEN_ cannot exceed 65535 (0xffff). Responses can be quite large (e.g. the background scan results log page) and this option can be used to limit the amount of information re‐ turned. ### -n --name decode some log pages into 'name=value' entries, one per line. The name contains no space and may be abbreviated and the value is decimal unless prefixed by '0x'. Nesting is indicated by leading spaces. This form is meant to be relatively easy to parse. ### -x --no_inq suppresses the output of information obtained from an initial call to the INQUIRY com‐ mand for the standard response. The default (assuming some other options that suppress this output are also not given) is to output several device identification strings. If this option is given twice (or more) then no INQUIRY command is sent hence there will be no device identification string output either. Also the peripheral device type (PDT) field will not be obtained so this utility will not be able to differentiate be‐ tween some log pages that are device dependent. It will assume a PDT of 0 (i.e. a disk). ### -O --old Switch to older style options. Please use as first option. ### -p --page log page name/number to access. _PG_ is either an acronym, a page number, or a page, subpage number pair. Available acronyms can be listed with the _--enumerate_ option. Page (0 to 63) and subpage (0 to 255) numbers are comma separated. They are decimal unless a hexadecimal indication is given. A hexadecimal number can be specified by a leading "0x" or a trailing "h". A few acronyms specify a range of subpage values in which case the acronym may be fol‐ lowed by a comma then a subpage number. This method can also be used to fetch the Sup‐ ported subpages log page (e.g. --page=temp,0xff). ### -P --paramp _PP_ is the parameter pointer value to place in a field of that name in the LOG SENSE cdb. A decimal number in the range 0 to 65535 (0xffff) is expected. When a value greater than 0 is given the _--ppc_ option should be selected. The default value is 0. ### -q --pcb show Parameter Control Byte settings (only relevant when log parameters being output in ASCII). ### -Q --ppc sets the Parameter Pointer Control (PPC) bit in the LOG SENSE cdb. Default is 0 (i.e. cleared). This bit was made obsolete in SPC-4 revision 18. ### -D --pdt _DT_ is the peripheral device type that is used when it is not available from the _DE‐_ _VICE_. There are two main cases of this: with the _--pdt=DT_ without a _DEVICE_ and when _--no_inq_ is used with a _DEVICE_. ### -r --raw output the response in binary to stdout. Error messages and warnings are output to stderr. This option may also be given together with _--in=FN_ in which case the contents of _FN_ are interpreted as binary data (and the response is decoded as normal, not dumped as binary). ### -R --readonly open the _DEVICE_ read-only (e.g. in Unix with the O_RDONLY flag). The default action is to try and open _DEVICE_ read-write then if that fails try to open again with read-only. However when a read-write open succeeds there may still be unwanted actions on the close (e.g. some OSes try to do a SYNCHRONIZE CACHE command). So this option forces a read-only open on _DEVICE_ and if it fails, this utility will exit. Note that options like _--select_ most likely need a read-write open. ### -R --reset use SCSI LOG SELECT command (with the PCR bit set) to reset the all log pages (or the given page). Exactly what is reset depends on the accompanying SP bit (i.e. _--sp_ op‐ tion which defaults to 0) and the _PC_ ("page control") value (which defaults to 1). Supplying this option implies the _--select_ option as well. This option seems to clear error counter log pages but leaves pages like self-test results, start-stop cycle counter and temperature log pages unaffected. This option may be required to clear log pages if a counter reaches its maximum value since the log page in which the counter is found will remain "stuck" at its maximum value until some user interaction (e.g. calling sg_logs with this option). ### -S --select use a LOG SELECT command. The default action (i.e. when neither this option nor _--re‐_ _set_ is given) is to do a LOG SENSE command. See the LOG SELECT section. ### -s --sp sets the Saving Parameters (SP) bit. Default is 0 (i.e. cleared). When set this in‐ structs the device to store the current log page parameters (as indicated by the DS and TSD parameter codes) in some non-volatile location. Hence the log parameters will be preserved across power cycles. This option is typically not needed, especially if the GLTSD flag is clear in the control mode page as this instructs the device to peri‐ odically save all saveable log parameters to non-volatile locations. ### -t --temperature outputs the temperature. First looks in the temperature log page and if that is not available tries the Informational Exceptions log page which may also have the current temperature (especially on older disks). ### -T --transport outputs the transport ('Protocol specific port') log page. Equivalent to setting '--page=18h'. ### -M --vendor where _VP_ is a vendor/manufacturer (e.g. "sea" for Seagate) or product (group) acronym (e.g. "lto5" for the 5th generation LTO (tape) consortium). Either the whole log page is vendor specific (e.g. page numbers 0x30 to 0x3f) or part of a T10 defined log page is vendor specific. For example SPC-5 defines parameter code 0x0 of page 0x2f (the Informational Exceptions log page) and states that the remaining parameter codes (i.e. 0x1 to 0xffff) are vendor specific. Using a _VP_ of "xxx" will list the available acronyms. If this option is used with _--page=PG_ and _PG_ is an acronym then this option is ig‐ nored. If _PG_ is a number (e.g. 0xc0) then _VP_ is used to choose the which vendor spe‐ cific page (e.g. sharing page number 0xc0) to decode. ### -v --verbose increase level of verbosity. When used with _--enumerate_, in the list of known log page names, those that have no associated decode logic are followed by "[hex only]". ### -V --version print out version string then exit. ## LOG SELECT The SCSI LOG SELECT command can be used to reset certain parameters to vendor specific de‐ faults, save them to non-volatile storage (i.e. the media), or supply new page contents. This command has changed between SPC-3 and SPC-4 with the addition of the Page and Subpage Code fields which can only be non zero when the Parameter list length is zero. The _--select_ (or _--reset_) option is required to issue a LOG SELECT command. If the _--in=FN_ option is not given (or _FN_ is effectively empty) then the Parameter list length field is set to zero. If the _--in=FN_ option is is given then its decoded data is placed in the data-out buffer and its length in bytes is placed in the Parameter list length field. Other options that are active with the LOG SELECT command are _--control=PC_, _--reset_ (which sets the PCR bit) and _--sp_. ## APPLICATION CLIENT This is the name of a log page that acts as a container for data provided by the user. An ap‐ plication client is a SCSI term for the program that issues commands to a SCSI initiator (of‐ ten known as a Host Bus Adapter (HBA)). So, for example, this utility is a SCSI application client. The Application Client log page has 64 log parameters with parameters codes 0 to 63. Each can hold 252 bytes of user binary data. That 252 bytes (or less) of user data, with a 4 byte pre‐ fix (for a total of 256 bytes) can be provided with the _--in=FN_ option. A typical prefix would be '0,n,83,fc'. The "n" is the parameter code in hex so the last log parameter would be '0,3f,83,fc'. That log parameter could be read back at some later time with '--page=0xf --filter=0x'. ## NOTES This utility will usually do a double fetch of log pages with the SCSI LOG SENSE command. The first fetch requests a 4 byte response (i.e. place 4 in the "allocation length" field in the cdb). From that response it can calculate the actual length of the response which is what it asks for on the second fetch. This is typical practice in SCSI and guaranteed to work in the standards. However some older devices don't comply. For those devices using the _--maxlen=LEN_ option will do a single fetch. A value of 252 should be a safe starting point. Various log pages hold information error rates, device temperature, start stop cycles since the device was produced and the results of the last 20 self tests. Self tests can be initi‐ ated by the [sg_senddiag(8)](https://www.chedong.com/phpMan.php/man/sgsenddiag/8/markdown) utility. The smartmontools package provides much of the informa‐ tion found with sg_logs in a form suitable for monitoring the health of SCSI disks and tape drives. The simplest way to find which log pages can be decoded by this utility is to use the _--enu‐_ _merate_ option. Some page names are known but there is no decode logic; such cases have "[hex only]" after the log page name when the _--verbose_ option is given with _--enumerate_. ## EXIT STATUS The exit status of sg_logs is 0 when it is successful. Otherwise see the [sg3_utils(8)](https://www.chedong.com/phpMan.php/man/sg3utils/8/markdown) man page. ## OLDER COMMAND LINE OPTIONS The options in this section were the only ones available prior to sg3_utils version 1.23 . Since then this utility defaults to the newer command line options which can be overridden by using _--old_ (or _-O_) as the first option. See the ENVIRONMENT VARIABLES section for another way to force the use of these older command line options. Options with arguments or with two or more letters can have an extra '-' prepended. For exam‐ ple: both '-pcb' and '--pcb' are acceptable. ### -a description. ### -A --all' in the main description. ### -c ### -e _--enumerate_ in the main description. ### -h stead. ### -i resenting a log page that will be sent as parameter data of a LOG SELECT command. See the LOG SELECT section. ### -H ### -l _--list_ in the main description. ### -L lent to '--list --list' in the main description. ### -m is available. _LEN_ is decimal unless it has a leading '0x' or trailing 'h'. Equivalent to _--maxlen=LEN_ in the main description. ### -M ### -n ### -N --new Switch to the newer style options. ### -p pair. Available acronyms can be listed with the _--enumerate_ option. Page (0 to 3f) and subpage (0 to ff) numbers are comma separated. The numbers are assumed to be hexadeci‐ mal. ### -paramp _PP_ is the parameter pointer value (in hex) to place in command. Should be a number between 0 and ffff inclusive. ### -pcb in ASCII). ### -ppc ### -r page). Equivalent to _--reset_ in the main description. ### -R ### -select use a LOG SELECT command. Equivalent to _--select_ in the main description. ### -sp in the main description. ### -t ### -T in the main description. ### -v ### -V ### -x **-? **output usage message then exit. ## ENVIRONMENT VARIABLES Since sg3_utils version 1.23 the environment variable SG3_UTILS_OLD_OPTS can be given. When it is present this utility will expect the older command line options. So the presence of this environment variable is equivalent to using _--old_ (or _-O_) as the first command line op‐ tion. ## AUTHOR Written by Douglas Gilbert ## REPORTING BUGS Report bugs to . ## COPYRIGHT Copyright © 2002-2020 Douglas Gilbert This software is distributed under the GPL version 2. There is NO warranty; not even for MER‐ CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. ## SEE ALSO ### smartctl(smartmontools), [sg_senddiag(8)](https://www.chedong.com/phpMan.php/man/sgsenddiag/8/markdown) sg3_utils-1.45 January 2020 [_SG_LOGS_(8)](https://www.chedong.com/phpMan.php/man/SGLOGS/8/markdown)