sg3_utils.8

.TH SG3_UTILS "8" "March 2007" "sg3_utils\-1.24" SG3_UTILS
.SH NAME
sg3_utils \- a package of utilities for sending SCSI commands
.SH SYNOPSIS
.B sg_*
[\fI\-\-help\fR] [\fI\-\-hex\fR] [\fI\-\-raw\fR] [\fI\-\-verbose\fR]
[\fI\-\-version\fR] [\fIOTHER_OPTIONS\fR] \fIDEVICE\fR
.SH DESCRIPTION
.\" Add any additional description here
.PP
sg3_utils is a package of utilities that send SCSI commands to the given
\fIDEVICE\fR via a SCSI pass through interface provided by the host
operating system.
.PP
The names of all utilities start with "sg" and most start with "sg_" often
followed by the name or a shortening of the name of the SCSI command that
they send. For example the "sg_verify" utility sends the SCSI VERIFY
command. A mapping between SCSI commands and the sg3_utils utilities that
issue them is shown in the COVERAGE file.
.PP
SCSI draft standards can be found at http://www.t10.org . The standards
themselves can be purchased from ANSI and other standards organizations.
A good overview of various SCSI standards can be seen in
http://www.t10.org/scsi\-3.htm with the SCSI command sets in the upper part
of the diagram. SCSI commands in common with all device types can be found
in SPC of which SPC\-4 is the latest major version. Block device specific
commands (e.g.  as used by disks) are in SBC, those for tape drives in
SSC and those for CD/DVD drives in MMC. 
.PP
There are two generations of command line option usage. The newer
utilities (written since July 2004) use the getopt_long() function to parse
command line options. With that function, each option has two representations:
a short form (e.g. '\-v') and a longer form (e.g. '\-\-verbose'). If an
argument is required then it follows a space (optionally) in the short form
and a "=" in the longer form (e.g. in the sg_verify utility '\-l 2a6h'
and '\-\-lba=2a6h' are equivalent). Note that with getopt_long(), short form
options can be elided, for example: '\-all' is equivalent to '\-a \-l \-l'.
The \fIDEVICE\fR argument may appear after, between or prior to any options.
.PP
The older utilities, such as sg_inq, had individual command line processing
code (often found at the top of the main() function) based on a single "\-"
followed by one or more characters. If an argument is needed then it follows
a "=" (e.g. '\-p=1f' in sg_modes). Various options can be elided as long as
it is not ambiguous (e.g. '\-vv' to increase the verbosity).
.PP
Over time the command line interface of these older utilities became messy
and overloaded with options. So in sg3_utils version 1.23 the command line
interface of these older utilities was altered to have both a cleaner
getopt_long() interface and their older interface for backward compatibility.
By default these older utilities use their getopt_long() based interface.
That can be overridden by defining the SG3_UTILS_OLD_OPTS environment
variable or using '\-O' or '\-\-old' as the first command line option. The
man pages of the older utilities documents the details.
.PP
Several sg3_utils utilities are based on the Unix dd command (e.g. sg_dd)
and share dd's rather quirky command line interface.
.SH EXIT STATUS
To aid scripts that call these utilities, the exit status is set to indicate
success (0) or failure (1 or more). Note that some of the lower values
correspond to the SCSI sense key values to which they correspond. The exit
status values are:
.TP
.B 0
success
.TP
.B 1
syntax error. Either illegal command line options, options with bad
arguments or a combination of options that is not permitted.
.TP
.B 2
the \fIDEVICE\fR reports that it is not ready for the operation
requested. The device may be in the process of becoming ready (e.g.
spinning up but not at speed) so the utility may work after a wait.
.TP
.B 3
the \fIDEVICE\fR reports a medium or hardware error (or a blank check). For
example an attempt to read a corrupted block on a disk will yield this value.
.TP
.B 5
the \fIDEVICE\fR reports an "illegal request" with an additional sense code
other than "invalid command operation code". This is often a supported
command with a field set requesting an unsupported capability. For commands
that require a "service action" field this value can indicate that the
command with that service action value is not supported.
.TP
.B 6
the \fIDEVICE\fR reports a "unit attention" condition. This usually indicates
that something unrelated to the requested command has occurred (e.g. a device
reset) potentially before the current SCSI command was sent. The requested
command has not been executed by the device. Note that unit attention
conditions are usually only reported once by a device.
.TP
.B 9
the \fIDEVICE\fR reports an illegal request with an additional sense code
of "invalid command operation code" which means that it doesn't support the
requested command.
.TP
.B 11
the \fIDEVICE\fR reports an aborted command. In some cases aborted
commands can be retried immediately (e.g. if the transport aborted
the command due to congestion).
.TP
.B 15
the utility is unable to open, close or use the given \fIDEVICE\fR.
The given file name could be incorrect or there may be permission
problems. Adding the '\-v' option may give more information.
.TP
.B 20
the \fIDEVICE\fR reports it has a check condition but "no sense"
and non\-zero information in its additional sense codes. Some polling
commands (e.g. REQUEST SENSE) can receive this response.
.TP
.B 21
the \fIDEVICE\fR reports a "recovered error". The requested command
was successful. Most likely a utility will report a recovered error
to stderr and continue, probably leaving the utility with an exit
status of 0 .
.TP
.B 33
the command sent to \fIDEVICE\fR has timed out.
.TP
.B 97
the response to a SCSI command failed sanity checks.
.TP
.B 98
the \fIDEVICE\fR reports it has a check condition but the error
doesn't fit into any of the above categories.
.TP
.B 99
any errors that can't be categorized into values 1 to 98 may yield
this value. This includes transport and operating system errors
after the command has been sent to the device.
.PP
Most of the error conditions reported above will be repeatable (an
example of one that is not is "unit attention") so the utility can
be run again with the '\-v' option (or several) to obtain more
information.
.SH COMMON OPTIONS
Arguments to long options are mandatory for short options as well. In the
short form an argument to an option uses zero or more spaces as a
separator (i.e. the short form does not use "=" as a separator).
.PP
If an option takes a numeric argument then that argument is assumed to
be decimal unless otherwise indicated (e.g. with a leading "0x", a
trailing "h" or as noted in the usage message).
.TP
\fB\-h\fR, \fB\-?\fR, \fB\-\-help\fR
output the usage message then exit. In a few older utilities the '\-h'
option requests hexadecimal output. In these cases the '\-?' option will
output the usage message then exit.
.TP
\fB\-H\fR, \fB\-\-hex\fR
for SCSI commands that yield a non\-trivial response, print out that
response in ASCII hexadecimal.
.TP
\fB\-r\fR, \fB\-\-raw\fR
for SCSI commands that yield a non\-trivial response, output that response
in binary to stdout. If any error messages or warning are produced they are
usually sent to stderr. Some utilities that consume data to send to the
device along with the SCSI command, use this option to provide that data
or indicate that it can be read from stdin.
.TP
\fB\-v\fR, \fB\-\-verbose\fR
increase the level of verbosity, (i.e. debug output). Can be used multiple
times to further increase verbosity. The additional output is usually sent
to stderr.
.TP
\fB\-V\fR, \fB\-\-version\fR
print the version string and then exit. Each utility has its own version
number and date of last code change.
.SH AUTHORS
Written by Douglas Gilbert.
.SH "REPORTING BUGS"
Report bugs to <dgilbert at interlog dot com>.
.SH COPYRIGHT
Copyright \(co 1999\-2007 Douglas Gilbert
.br
Some utilities are distributed under a GPL version 2 license while
others, usually more recent ones, are under a FreeBSD license. The files
that are common to almost all utilities and thus contain the most reusable
code, namely sg_lib.[hc], sg_cmds_basic.[hc] and sg_cmds_extra.[hc] are
under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.
.SH "SEE ALSO"
.B sdparm(sdparm)