SG_OPCODES(8) SG3_UTILS SG_OPCODES(8)
NAME
sg_opcodes - report supported SCSI commands or task management func-
tions
SYNOPSIS
sg_opcodes [--alpha] [--compact] [--enumerate] [--help] [--hex]
[--mask] [--mlu] [--no-inquiry] [--opcode=OP[,SA]] [--pdt=DT] [--raw]
[--rctd] [--repd] [--sa=SA] [--tmf] [--unsorted] [--verbose] [--ver-
sion] DEVICE
sg_opcodes [-a] [-c] [-e] [-H] [-m] [-M] [-n] [-o=OP] [-p=DT] [-q] [-R]
[-s=SA] [-t] [-u] [-v] [-V] [-?] DEVICE
DESCRIPTION
This utility sends a SCSI REPORT SUPPORTED OPERATION CODES or a REPORT
SUPPORTED TASK MANAGEMENT FUNCTIONS command to the DEVICE and then out-
puts the response. The default action is to report supported operation
codes. In this mode it will either list all supported commands or give
detailed information on a specific command identified by the --op-
code=OP option (perhaps with additional information from the --sa=SA
option).
The name of a SCSI command depends on its peripheral device type (e.g.
a disk). The REPORT SUPPORTED OPERATION CODES and REPORT SUPPORTED TASK
MANAGEMENT FUNCTIONS commands are not supported in the MMC command set
for CD and DVD devices. This utility does an INQUIRY to obtain the pe-
ripheral device type and prints out the vendor, product and revision
strings.
A similar facility to query supported operation codes previously was
available via the CmdDt bit in the SCSI INQUIRY command (see
sg_inq(8)). However that facility was made obsolete and replaced by the
REPORT SUPPORTED OPERATION CODES command in SPC-3 (revision 4) during
February 2002.
This utility supports two command line syntaxes, the preferred one is
shown first in the synopsis and explained in this section. A later sec-
tion on the old command line syntax outlines the second group of op-
tions.
OPTIONS
Arguments to long options are mandatory for short options as well.
-a, --alpha
when all supported commands are being listed there is no re-
quirement for the device server (i.e. the DEVICE) to sort the
list of commands. When this option is given the list of sup-
ported commands is sorted by name (alphabetically). When this
option and the --unsorted option are both _not_ given then the
list of supported commands is sorted numerically (first by oper-
ation code and then by service action).
-c, --compact
some command names, especially those associated with some ser-
vice actions, are getting longer. This may cause line wrap in
the one line per command mode on some terminals. When this op-
tion is given the opcode and service action fields are combined
into a single field with the service action, prefixed by a comma
shown directly after the opcode. If there is no service action
associated with the command, then the comma and the service ac-
tion are not shown after the opcode. The CDB size field is not
shown when this option is given.
-e, --enumerate
this option prints the name of the SCSI command based on the
given opcode, peripheral device type and optionally the service
action. If given, DEVICE is ignored. The opcode, peripheral de-
vice type and service action default to zero if not given. Thus
if this option is the only option given then "Test Unit ready"
is output since its opcode is 0, it has no service action and it
is common to all peripheral device types since it is defined in
the SCSI Primary Commands (SPC) standard(s).
-h, --help
outputs the usage message summarizing command line options then
exits. Ignores DEVICE if given.
-H, --hex
outputs the response in ASCII hexadecimal to stdout.
-m, --mask
additionally prints out the cdb mask in hex. So a 12 byte cdb
will have a 12 byte hexadecimal mask. If the hexadecimal is ex-
panded (mentally) to binary then a "1" means the corresponding
position in the cdb may be set. And "0" means the corresponding
position in the cdb must not be set. For "0" mask positions that
a user tries to set in a cdb, the device may either ignore it or
report an error, typically with a sense key of "illegal re-
quest".
-M, --mlu
additionally prints out an indication (0 or 1) whether the com-
mand effects all logical units in the containing target. MLU
(Multiple Logical Units) is a bit in the REPORT SUPPORTED OPERA-
TION CODES response introduced by proposal 18-045r1 (and possi-
bly in spc5r20). Without the option, the default output format
which lists all opcodes, does not include a MLU indication.
-n, --no-inquiry
Prior to calling a SCSI REPORT SUPPORTED OPERATION CODES or a
REPORT SUPPORTED TASK MANAGEMENT FUNCTIONS command, a SCSI IN-
QUIRY command is performed. The reason is to determine the pe-
ripheral device type (pdt) of the DEVICE as this is helpful in
translating operation codes to the command names. By default
this utility prints a summary of INQUIRY command response on
stdout. If this option (or the --raw option) is given then that
summary is not printed on stdout.
-O, --old
Switch to older style options. Please use as first option.
-o, --opcode=OP[,SA]
the DEVICE will be queried for the given operation code (i.e.
the OP value) which is the first byte of a SCSI command. Option-
ally, if a SA value is given, it will be used as that SCSI com-
mand's service action. Note that OP and OP,0 are not the same
thing, as SCSI does allow the service action to be 0 (but it is
not comman). OP and SA are decimal unless prefixed by "0x" or
they have a trailing "h". OP should be in the range 0 to 255
(0xff) inclusive. SA should be in the range 0 to 65535 (0xffff)
inclusive. When this option is not given then all available SCSI
commands supported by the DEVICE are listed.
-p, --pdt=DT
where DT is the peripheral device type. This is used together
with the --enumerate to differentiate when a command opcode (and
perhaps service action) is shared by multiple device types.
This option may also be used with the --no-inquiry option to
suppress this utility doing an INQUIRY command since the main
reason for doing that is to find the peripheral device type of
the DEVICE.
-r, --raw
output the response in binary to stdout. Error messages and
warnings, if any, are sent to stderr.
-R, --rctd
set report command timeout descriptor (RCTD) bit in the cdb. The
response may or may not contain command timeout descriptors. If
available they are output. If supported there are two values: a
nominal command timeout and a recommended command timeout. Both
have units of seconds. A value of zero means that no timeout is
indicated and this is shown in the corresponding decoded output
as "-".
-q, --repd
set read extended parameter data (REPD) bit in the report task
management functions cdb. 16 bytes rather than the default 4
bytes expected in the response. This was added in SPC-4 (revi-
sion 26).
-s, --sa=SA
the DEVICE will be queried for a command with the given service
action (i.e. the SA value). Used in conjunction with the --op-
code=OP option. If this option is not given, --opcode=OP is
given and the command in question does have a service action
then a value of 0 will be assumed. SA is decimal and expected to
be in the range 0 to 65535 (0xffff) inclusive.
-t, --tmf
list supported task management functions. This is done with the
SCSI REPORT SUPPORTED TASK MANAGEMENT FUNCTIONS command. When
this option is chosen the --alpha, --opcode=OP, --rctd, --sa=SA
and --unsorted options are ignored.
-u, --unsorted
when all supported commands are being listed there is no re-
quirement for the device server (i.e. the DEVICE) to sort the
list of commands. When this option is given the list of sup-
ported commands is in the order given by the DEVICE. When this
option is not given the supported commands are sorted numeri-
cally (first by operation code and then by service action).
-v, --verbose
increase level of verbosity. Can be used multiple times.
-V, --version
print out version string then exit.
NOTES
As of SPC-5 revision 8 the recognized task management functions are:
abort set, abort task set, clear ACA, clear task set, logical unit re-
set, query task, query asynchronous event, query task set, and I_T
nexus reset. In SPC-4 revision 26 target reset and wakeup task manage-
ment functions were made obsolete.
In the 2.4 series of Linux kernels the DEVICE must be a SCSI generic
(sg) device. In the 2.6 series block devices (e.g. SCSI disks and DVD
drives) can also be specified. For example "sg_opcodes /dev/sda" will
work in the 2.6 series kernels.
EXIT STATUS
The exit status of sg_opcodes is 0 when it is successful. Otherwise see
the sg3_utils(8) man page.
OLDER COMMAND LINE OPTIONS
The options in this section were the only ones available prior to
sg3_utils version 1.23 . Since then this utility defaults to the newer
command line options which can be overridden by using --old (or -O) as
the first option. See the ENVIRONMENT VARIABLES section for another way
to force the use of these older command line options.
-a sort command alphabetically. Equivalent to --alpha in main de-
scription.
-c see the --compact option above.
-e see the --enumerate option above.
-H see the --hex option above.
-m see the --mask option above.
-n don't print a summary of the SCSI INQUIRY response on stdout.
-N, --new
Switch to the newer style options.
-o=OP the DEVICE will be queried for the given operation code (i.e.
OP) which is the first byte of a SCSI command. OP is hexadecimal
and expected to be in the range 0 to ff inclusive. When this
option is not given then all available SCSI commands supported
by the DEVICE are listed.
-p=DT see the --pdt=DT option above.
-q set the read extended parameter data (REPD) bit in report TMF
cdb. Equivalent to --repd in main description.
-R set the report command timeout descriptor (RCTD) bit in cdb.
Equivalent to --rctd in main description.
-s=SA the DEVICE will be queried for a command with the given service
action (i.e. SA). Used in conjunction with the -o=OP option. If
this option is not given, -o=OP is given and the command in
question does have a service action then a value of 0 will be
assumed. SA is hexadecimal and expected to be in the range 0 to
ffff inclusive.
-t list supported task management functions. Equivalent to --tmf in
the main description.
-u output all supported commands in the order given by DEVICE.
Equivalent to --unsorted in main description.
-v increase level of verbosity. Can be used multiple times.
-V print out version string then exit.
-? output usage message. Ignore all other parameters.
EXAMPLES
The examples in this page use Linux device names. For suitable device
names in other supported Operating Systems see the sg3_utils(8) man
page.
To see the information about a specific command give its operation code
to the '--op=' option. A command line invocation is shown first fol-
lowed by a typical response:
# sg_opcodes --op=93h /dev/sdb
Opcode=0x93
Command_name: Write same(16)
Command supported [conforming to SCSI standard]
Usage data: 93 e2 00 00 00 00 ff ff ff ff 00 00 ff ff 00 00
The next example shows the supported task management functions:
# sg_opcodes --tmf -n /dev/sdb
Task Management Functions supported by device:
Abort task
Abort task set
Clear ACA
Clear task set
Logical unit reset
Query task
Enumerate can be used to look up a SCSI command name in the absence of
a device that supports that command. The opcode and service action (if
required) should be supplied:
# sg_opcodes --enumerate --op=0x9b,0xa
SCSI command:
Read buffer(16), read data from echo buffer
ENVIRONMENT VARIABLES
Since sg3_utils version 1.23 the environment variable
SG3_UTILS_OLD_OPTS can be given. When it is present this utility will
expect the older command line options. So the presence of this environ-
ment variable is equivalent to using --old (or -O) as the first command
line option.
AUTHOR
Written by Douglas Gilbert
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright © 2004-2021 Douglas Gilbert
This software is distributed under the GPL version 2. There is NO war-
ranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
POSE.
SEE ALSO
sg_inq(sg3_utils)
sg3_utils-1.46 March 2020 SG_OPCODES(8)
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