# sg_sync - send SCSI SYNCHRONIZE CACHE command - man(8) - [phpMan]

[_SG_SYNC_(8)](https://www.chedong.com/phpMan.php/man/SGSYNC/8/markdown)                                    SG3_UTILS                                   [_SG_SYNC_(8)](https://www.chedong.com/phpMan.php/man/SGSYNC/8/markdown)

## NAME
       sg_sync - send SCSI SYNCHRONIZE CACHE command

## SYNOPSIS
       **sg_sync  **[_--16_]  [_--count=COUNT_]  [_--group=GN_]  [_--help_]  [_--immed_]  [_--lba=LBA_]  [_--sync-nv_]
       [_--timeout=SECS_] [_--verbose_] [_--version_] _DEVICE_

## DESCRIPTION
       Send SYNCHRONIZE [CACHE(10)](https://www.chedong.com/phpMan.php/man/CACHE/10/markdown) or SYNCHRONIZE [CACHE(16)](https://www.chedong.com/phpMan.php/man/CACHE/16/markdown) command to _DEVICE_.   These  commands  are
       defined  for  SCSI block devices (see SBC-3). If successful these commands make sure that any
       blocks whose latest versions are held in cache are written to (also termed  as  "synchronized
       with") the medium.

       If  the  _LBA_  and _COUNT_ arguments are both zero (their defaults) then all blocks in the cache
       are synchronized. If _LBA_ is greater than zero while _COUNT_ is zero then blocks  in  the  cache
       whose addresses are from and including _LBA_ to the highest lba on the device are synchronized.
       If  both _LBA_ and _COUNT_ are non zero then blocks in the cache whose addresses lie in the range
       _LBA_ to _LBA_+_COUNT_-1 inclusive are synchronized with the medium.

## OPTIONS
       Arguments to long options are mandatory for short options as well.

### -S --16
              performs a  SYNCHRONIZE  [CACHE(16)](https://www.chedong.com/phpMan.php/man/CACHE/16/markdown)  command.  Default  is  to  perform  a  SYNCHRONIZE
              [CACHE(10)](https://www.chedong.com/phpMan.php/man/CACHE/10/markdown) command.

### -c --count
              where  _COUNT_  is  the  number of blocks to synchronize from and including _LBA_. Default
              value is 0. When 0 then all blocks in the cache from and including _LBA_ argument to the
              highest block address are synchronized.

### -g --group
              where _GN_ is the group number which can be between 0 and  63  inclusive.   The  default
              value  is  0  .  Group numbers are used to segregate data collected within the device.
              This is a new feature in SBC-2 and can probably be ignored for the time being.

### -h --help
              output the usage message then exit.

### -i --immed
              sets the IMMED bit in the SYNCHRONIZE CACHE command. This instructs the device, if the
              format of the command is acceptable, to return a GOOD status immediately  rather  than
              wait for the blocks in the cache to be synchronized with (i.e. written to) the medium.

### -l --lba
              where  _LBA_  is  the  lowest  logical  block address in the cache to synchronize to the
              medium. Default value is 0 .

### -s --sync-nv
              synchronize the (volatile) cache with the non-volatile cache. Without this option  (or
              if  there  is  no  non-volatile  cache  in the device) the synchronization is with the
              medium. The SYNC_NV bit was made obsolete in SBC-3 revision 35d.

### -t --timeout
              where _SECS_ is the number of seconds the OS allows the SYNCHRONIZE  [CACHE(16)](https://www.chedong.com/phpMan.php/man/CACHE/16/markdown)  to  com‐
              plete  before  it tries to cancel the command. Cancelling commands (typically with the
              task management function "abort task") is best avoided. Note this option is  only  ac‐
              tive  together  with  the _--16_ option. The default timeout is 60 seconds for both SYN‐
              CHRONIZE [CACHE(10)](https://www.chedong.com/phpMan.php/man/CACHE/10/markdown) and SYNCHRONIZE [CACHE(16)](https://www.chedong.com/phpMan.php/man/CACHE/16/markdown). Note that timeout issues can be  avoided
              with the _--immed_ option.

### -v --verbose
              increase the level of verbosity, (i.e. debug output).

### -V --version
              print the version string and then exit.

## NOTES
       With  the  SYNCHRONIZE  [CACHE(16)](https://www.chedong.com/phpMan.php/man/CACHE/16/markdown) command _LBA_ can be up to 64 bits in size and _COUNT_ up to 32
       bits in size. With the SYNCHRONIZ [CACHE(10)](https://www.chedong.com/phpMan.php/man/CACHE/10/markdown) command _LBA_ can be up to  32  bits  in  size  and
       _COUNT_ up to 16 bits in size.

       Various numeric arguments (e.g. _LBA_) may include multiplicative suffixes or be given in hexa‐
       decimal. See the "NUMERIC ARGUMENTS" section in the [sg3_utils(8)](https://www.chedong.com/phpMan.php/man/sg3utils/8/markdown) man page.

## EXIT STATUS
       The  exit  status  of  sg_sync is 0 when it is successful. Otherwise see the [sg3_utils(8)](https://www.chedong.com/phpMan.php/man/sg3utils/8/markdown) man
       page.

## AUTHORS
       Written by Douglas Gilbert.

## REPORTING BUGS
       Report bugs to <dgilbert at interlog dot com>.

## COPYRIGHT
       Copyright © 2004-2018 Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO warranty; not even for MER‐
       CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

## SEE ALSO
### sg_start(sg3_utils)

sg3_utils-1.43                                May 2018                                    [_SG_SYNC_(8)](https://www.chedong.com/phpMan.php/man/SGSYNC/8/markdown)