.TH SG_SYNC "8" "July 2013" "sg3_utils\-1.37" SG3_UTILS
.SH NAME
sg_sync \- send SCSI SYNCHRONIZE CACHE command
.SH SYNOPSIS
.B sg_sync
[\fI\-\-16\fR] [\fI\-\-count=COUNT\fR] [\fI\-\-group=GN\fR]
[\fI\-\-help\fR] [\fI\-\-immed\fR] [\fI\-\-lba=LBA\fR] [\fI\-\-sync\-nv\fR]
[\fI\-\-timeout=SECS\fR] [\fI\-\-verbose\fR] [\fI\-\-version\fR] \fIDEVICE\fR
.SH DESCRIPTION
.\" Add any additional description here
.PP
Send SYNCHRONIZE CACHE(10) or SYNCHRONIZE CACHE(16) command to \fIDEVICE\fR.
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.
.PP
If the \fILBA\fR and \fICOUNT\fR arguments are both zero (their defaults)
then all blocks in the cache are synchronized. If \fILBA\fR is greater than
zero while \fICOUNT\fR is zero then blocks in the cache whose addresses are
from and including \fILBA\fR to the highest lba on the device are
synchronized. If both \fILBA\fR and \fICOUNT\fR are non zero then blocks in
the cache whose addresses lie in the range \fILBA\fR to
\fILBA\fR+\fICOUNT\fR\-1 inclusive are synchronized with the medium.
.SH OPTIONS
Arguments to long options are mandatory for short options as well.
.TP
\fB\-S\fR, \fB\-\-16\fR
performs a SYNCHRONIZE CACHE(16) command. Default is to perform a
SYNCHRONIZE CACHE(10) command.
.TP
\fB\-c\fR, \fB\-\-count\fR=\fICOUNT\fR
where \fICOUNT\fR is the number of blocks to synchronize from and including
\fILBA\fR. Default value is 0. When 0 then all blocks in the cache from and
including \fILBA\fR argument to the highest block address are synchronized.
.TP
\fB\-g\fR, \fB\-\-group\fR=\fIGN\fR
where \fIGN\fR is the group number which can be between 0 and 31 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.
.TP
\fB\-h\fR, \fB\-\-help\fR
output the usage message then exit.
.TP
\fB\-i\fR, \fB\-\-immed\fR
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.
.TP
\fB\-l\fR, \fB\-\-lba\fR=\fILBA\fR
where \fILBA\fR is the lowest logical block address in the cache to
synchronize to the medium. Default value is 0 .
.TP
\fB\-s\fR, \fB\-\-sync\-nv\fR
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.
.TP
\fB\-t\fR, \fB\-\-timeout\fR=\fISECS\fR
where \fISECS\fR is the number of seconds the OS allows the SYNCHRONIZE
CACHE(16) to complete 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 active together with the \fI\-\-16\fR
option. The default timeout is 60 seconds for both SYNCHRONIZE CACHE(10)
and SYNCHRONIZE CACHE(16). Note that timeout issues can be avoided with
the \fI\-\-immed\fR option.
.TP
\fB\-v\fR, \fB\-\-verbose\fR
increase the level of verbosity, (i.e. debug output).
.TP
\fB\-V\fR, \fB\-\-version\fR
print the version string and then exit.
.SH NOTES
With the SYNCHRONIZE CACHE(16) command \fILBA\fR can be up to 64 bits
in size and \fICOUNT\fR up to 32 bits in size. With the SYNCHRONIZ
CACHE(10) command \fILBA\fR can be up to 32 bits in size and \fICOUNT\fR
up to 16 bits in size.
.PP
Various numeric arguments (e.g. \fILBA\fR) may include multiplicative
suffixes or be given in hexadecimal. See the "NUMERIC ARGUMENTS" section
in the sg3_utils(8) man page.
.SH EXIT STATUS
The exit status of sg_sync is 0 when it is successful. Otherwise see
the sg3_utils(8) man page.
.SH AUTHORS
Written by Douglas Gilbert.
.SH "REPORTING BUGS"
Report bugs to <dgilbert at interlog dot com>.
.SH COPYRIGHT
Copyright \(co 2004\-2013 Douglas Gilbert
.br
This software is distributed under a FreeBSD license. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
.SH "SEE ALSO"
.B sg_start(sg3_utils)