SG_SYNC(8) SG3_UTILS SG_SYNC(8)NAME
sg_sync - send the scsi command synchronize cache
SYNOPSIS
sg_sync [--count=COUNT] [--group=GROUP] [--help] [--immed] [--lba=LBA] [--sync-nv] [--verbose] [--version] DEVICE
DESCRIPTION
Send SYNCHRONIZE CACHE (10) command to DEVICE. This command is defined for SCSI block devices (see SBC-2). If successful this command makes
sure that any blocks whose latest versions are held in (volatile) cache are written to (also termed as "synchronized with") the medium. If
the --sync-nv option is given and the device has a non-volatile cache then any blocks whose latest versions are held in volatile cache are
written to non-volatile cache.
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.
-c, --count=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
(volatile) cache from and including LBA argument to the highest block address are synchronized.
-g, --group=GROUP
where GROUP is the group number which can be between 0 and 31 inclusive. The default value is 0 . Group numbers are used to segre-
gate 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 (volatile) cache to be synchronized with (i.e. written to)
the medium (or the non-volatile cache).
-l, --lba=LBA
where LBA is the lowest logical block address in the (volatile) cache to synchronize to the medium (or the non-volatile cache).
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.
-v, --verbose
increase the level of verbosity, (i.e. debug output).
-V, --version
print the version string and then exit.
NOTES
Various numeric arguments (e.g. LBA) may include multiplicative suffixes or be given in hexadecimal. See the "NUMERIC ARGUMENTS" section in
the sg3_utils(8) man page.
EXIT STATUS
The exit status of sg_sync is 0 when it is successful. Otherwise see the sg3_utils(8) man page.
AUTHORS
Written by Douglas Gilbert.
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright (C) 2004-2009 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
POSE.
SEE ALSO
sg_start(sg3_utils)
sg3_utils-1.27 March 2009 SG_SYNC(8)
Check Out this Related Man Page
SG_VERIFY(8) SG3_UTILS SG_VERIFY(8)NAME
sg_verify - invoke SCSI VERIFY command(s) on a block device
SYNOPSIS
sg_verify [--bpc=BPC] [--count=COUNT] [--dpo] [--help] [--lba=LBA] [--verbose] [--version] [--vrprotect=VRP] DEVICE
DESCRIPTION
Sends one or more SCSI VERIFY commands to DEVICE. It is the 10 byte VERIFY command defined for block devices (see SBC-2 at
http://www.t10.org). Verify starts at the logical block address given by the --lba=LBA option and continues for --count=COUNT blocks. No
more than --bpc=BPC blocks are verified by each VERIFY command so if necessary multiple VERIFY commands are sent. No news is good news
(i.e. if there are no verify errors detected no messages are sent to stderr and the Unix return status is 0).
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.
-b, --bpc=BPC
where BPC specifies the maximum number of blocks that will be verified by a single SCSI VERIFY command. The default value is 128
blocks which equates to 64 KB for a disk with 512 byte blocks. If BPC is less than COUNT then multiple SCSI VERIFY commands are sent
to the device. For recent block devices (disks) this value may be constrained by the maximum transfer length field in the block lim-
its VPD page.
-c, --count=COUNT
where COUNT specifies the number of blocks to verify. The default value is 1 . If COUNT is greater than BPC (or its default value of
128) then multiple SCSI VERIFY commands are sent to the device. The sg_readcap utility can be used to find the maximum number of
blocks that a block device (e.g. a disk) has.
-d, --dpo
disable page out changes the cache retention priority of blocks read on the device's cache to the lowest priority. This means that
blocks read by other commands are more likely to remain in the device's cache.
-h, --help
output the usage message then exit.
-l, --lba=LBA
where LBA specifies the logical block address of the first block to start the verify operation. LBA is assumed to be decimal unless
prefixed by '0x' or a trailing 'h' (see below). The default value is 0 (i.e. the start of the device).
-v, --verbose
increase the level of verbosity, (i.e. debug output).
-V, --version
print the version string and then exit.
-P, --vrprotect=VRP
where VRP is the value in the vrprotect field in the VERIFY command cdb. It must be a value between 0 and 7 inclusive. The default
value is zero.
NOTES
The BPC, COUNT and LBA arguments may be followed by one of these multiplicative suffixes: c C *1; w W *2; b B *512; k K KiB *1,024; KB
*1,000; m M MiB *1,048,576; MB *1,000,000; g G GiB *1,073,741,824; GB *1,000,000,000; t T TiB *(2**40); TB *(10**12); p P PiB *(2**50) and
PB *(10**15). The "T" and "P" based suffixes can only be used for COUNT and LBA. Also a suffix of the form "x<n>" multiplies the leading
number by <n>.
Alternatively numerical values can be given in hexadecimal preceded by either "0x" or "0X" (or has a trailing "h" or "H"). When hex numbers
are given, multipliers cannot be used.
The amount of error correction and the number of retries attempted before a block is considered defective are controlled in part by the
Verify Error Recovery mode page. A note in the SBC-2 (draft) standard advises that to minimize the number of checks (and hence have the
most "sensitive" verify check) do the following in that mode page. Set the EER bit to 0, the PER bit to 1, the DTE bit to 1, the DCR bit to
1, the verify retry count to 0 and the verify error recovery timeout to 0. Mode pages can be modified with the sginfo utility.
EXIT STATUS
The exit status of sg_verify is 0 when it is successful. Otherwise see the sg3_utils(8) man page.
AUTHORS
Written by Douglas Gilbert.
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright (C) 2004-2007 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
POSE.
SEE ALSO
sginfo(sg3_utils), sg_modes(sg3_utils), sg_readcap(sg3_utils), sg_inq(sg3_utils)
sg3_utils-1.26 November 2007 SG_VERIFY(8)