NAME
sg_write_buffer - send a SCSI WRITE BUFFER command
SYNOPSIS
sg_write_buffer [--help] [--id=ID] [--in=FILE] [--length=LEN]
[--mode=MO] [--offset=OFF] [--raw] [--skip=SKIP] [--verbose]
[--version] DEVICE
DESCRIPTION
Sends a SCSI WRITE BUFFER command to DEVICE, along with data provided
by the user. In some cases no data is required, or data can be read
from the file given in the --in=FILE option, or data is read from stdin
when either --raw or --in=- is given.
Some WRITE BUFFER command variants do not have associated data to send
to the device, for example "activate_mc" ("activate deferred
microcode").
OPTIONS
Arguments to long options are mandatory for short options as well.
-h, --help
output the usage message then exit. If used multiple times also
prints the mode names and their acronyms.
-i, --id=ID
this option sets the buffer id field in the cdb. ID is a value
between 0 (default) and 255 inclusive.
-I, --in=FILE
read data from file FILE that will be sent with the WRITE BUFFER
command. If FILE is ’-’ then stdin is read until an EOF is
detected (this is the same action as --raw).
-l, --length=LEN
where LEN is the length, in bytes, of data to be written to the
device. If not given (and length cannot be deduced from
--in=FILE or --raw) then defaults to zero. If the option is
given and the length deduced from --in=FILE or --raw is less (or
no data is provided), then bytes of 0xff are used as fill bytes.
-m, --mode=MO
this option sets the mode field in the cdb. MO is a value
between 0 (default) and 31 inclusive. Alternatively an
abbreviation can be given. To list the available mode
abbreviations give an invalid one (e.g. ’--mode=xxx’) or use the
’-hh’ option.
-o, --offset=OFF
this option sets the buffer offset field in the cdb. OFF is a
value between 0 (default) and 2**24-1 . It is a byte offset.
-r, --raw
read data from stdin until an EOF is detected. This data is sent
with the WRITE BUFFER command to DEVICE. The action of this
option is the same as using ’--in=-’.
-s, --skip=SKIP
this option is only active when --in=FILE is given and FILE is a
regular file, rather than stdin. Data is read starting at byte
offset SKIP to the end of file (or the amount given by
--length=LEN). If not given the byte offset defaults to 0 (i.e.
the start of the file).
-v, --verbose
increase the level of verbosity, (i.e. debug output).
-V, --version
print the version string and then exit.
NOTES
If no --length=LEN is given this utility reads up to 8 MiB of data from
the given file FILE (or stdin). If a larger amount of data is required
then the --length=LEN option should be given. The user should be aware
that most operating systems have limits on the amount of data that can
be sent with one SCSI command. In Linux this depends on the pass
through mechanism used (e.g. block SG_IO or the sg driver) and various
setting in sysfs in the linux lk 2.6 series (e.g.
/sys/block/sda/queue/max_sectors_kb).
Downloading incorrect microcode into a device has the ability to render
that device inoperable. One would hope that the device vendor verifies
the data before activating it. If the SCSI WRITE BUFFER command is
given values in its cdb (e.g. LEN) that are inappropriate (e.g. too
large) then the device should respond with a sense key of ILLEGAL
REQUEST and an additional sense code of INVALID FIELD in CDB. If a
WRITE BUFFER command (or a sequence of them) fails due to device vendor
verification checks then it should respond with a sense key of ILLEGAL
REQUEST and an additional sense code of COMMAND SEQUENCE ERROR.
All numbers given with options are assumed to be decimal.
Alternatively numerical values can be given in hexadecimal preceded by
either "0x" or "0X" (or has a trailing "h" or "H").
EXIT STATUS
The exit status of sg_write_buffer is 0 when it is successful.
Otherwise see the sg3_utils(8) man page.
AUTHORS
Written by Luben Tuikov and Douglas Gilbert.
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright © 2006-2007 Luben Tuikov and Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.
SEE ALSO
sg_read_buffer(sg3_utils)