SG_INQ(8) SG3_UTILS SG_INQ(8)
NAME
sg_inq - issue SCSI INQUIRY command and/or decode its response
SYNOPSIS
sg_inq [--ata] [--block=0|1] [--cmddt] [--descriptors] [--export]
[--extended] [--force] [--help] [--hex] [--id] [--inhex=FN] [--len=LEN]
[--long] [--maxlen=LEN] [--only] [--page=PG] [--raw] [--vendor] [--ver-
bose] [--version] [--vpd] DEVICE
sg_inq [-36] [-a] [-A] [-b] [--B=0|1] [-c] [-cl] [-d] [-e] [-f] [-h]
[-H] [-i] [-I=FN] [-l=LEN] [-L] [-m] [-M] [-o] [-p=VPD_PG] [-P] [-r]
[-s] [-u] [-v] [-V] [-x] [-36] [-?] DEVICE
DESCRIPTION
This utility, when DEVICE is given, sends a SCSI INQUIRY command to it
then outputs the response. All SCSI devices are meant to respond to a
"standard" INQUIRY command with at least a 36 byte response (in SCSI 2
and higher). An INQUIRY is termed as "standard" when both the EVPD and
CmdDt (now obsolete) bits are clear.
Alternatively the --inhex=FN option can be given. In this case FN is
assumed to be a file name ('-' for stdin) containing ASCII hexadecimal
representing an INQUIRY response.
This utility supports two command line syntaxes. The preferred one is
shown first in the synopsis and is described in the main OPTIONS sec-
tion. A later section titled OLDER COMMAND LINE OPTIONS describes the
second group of options.
An important "non-standard" INQUIRY page is the Device Identification
Vital Product Data (VPD) page [0x83]. Since SPC-3, support for this
page is mandatory. The --id option decodes this page. New VPD page in-
formation is no longer being added to this utility. To get information
on new VPD pages see the sg_vpd(8) or sdparm(8) utilities.
In Linux, if the DEVICE exists and the SCSI INQUIRY fails (e.g. because
the SG_IO ioctl is not supported) then an ATA IDENTIFY (PACKET) DEVICE
is tried. If it succeeds then device identification strings are output.
The --raw and --hex options can be used to manipulate the output. If
the --ata option is given then the SCSI INQUIRY is not performed and
the DEVICE is assumed to be ATA (or ATAPI). For more information see
the ATA DEVICES section below.
In some operating systems a NVMe device (e.g. SSD) may be given as the
DEVICE. For more information see the NVME DEVICES section below.
The reference document used for interpreting an INQUIRY is T10/BSR IN-
CITS 502 Revision 19 which is draft SPC-5 revision 19, 14 February
2018). It can be found at http://www.t10.org . Obsolete and reserved
items in the standard INQUIRY response output are displayed in square
brackets.
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.
-a, --ata
Assume given DEVICE is an ATA or ATAPI device which can receive
ATA commands from the host operating system. Skip the SCSI IN-
QUIRY command and use either the ATA IDENTIFY DEVICE command
(for non-packet devices) or the ATA IDENTIFY PACKET DEVICE com-
mand. To show the response in hex, add a '--verbose' option.
This option is only available in Linux.
-B, --block=0|1
this option controls how the file handle to the DEVICE is
opened. If this argument is 0 then the open is non-blocking. If
the argument is 1 then the open is blocking. In Unix a
non-blocking open is indicated by a O_NONBLOCK flag while a
blocking open is indicated by the absence of that flag. The de-
fault value depends on the operating system and the type of DE-
VICE node. For Linux pass-throughs (i.e. the sg and bsg drivers)
the default is 0.
-c, --cmddt
set the Command Support Data (CmdDt) bit (defaults to clear(0)).
Used in conjunction with the --page=PG option where PG specifies
the SCSI command opcode to query. When used twice (e.g. '-cc')
this utility forms a list by looping over all 256 opcodes (0 to
255 inclusive) only outputting a line for commands that are
found. The CmdDt bit is now obsolete; it has been replaced by
the REPORT SUPPORTED OPERATION CODES command, see the sg_op-
codes(8) utility.
-d, --descriptors
decodes and prints the version descriptors found in a standard
INQUIRY response. There are up to 8 of them. Version descriptors
indicate which versions of standards and/or drafts the DEVICE
complies with. The normal components of a standard INQUIRY are
output (typically from the first 36 bytes of the response) fol-
lowed by the version descriptors if any.
-e see entry below for --vpd.
-f, --force
As a sanity check, the normal action when fetching VPD pages
other than page 0x0 (the "Supported VPD pages" VPD page), is to
first fetch page 0x0 and only if the requested page is one of
the supported pages, to go ahead and fetch the requested page.
When this option is given, skip checking of VPD page 0x0 before
accessing the requested VPD page. The prior check of VPD page
0x0 is known to crash certain USB devices, so use with care.
-u, --export
prints out information obtained from the device. The output can
be modified by selecting a VPD page with PG (from --page=PG). If
the device identification VPD page 0x83 is given it prints out
information in the form: "SCSI_IDENT_<assoc>_<type>=<ident>" to
stdout. If the device serial number VPD page 0x80 is given it
prints out information in the form: "SCSI_SERIAL=<ident>". Other
VPD pages are not supported. If no VPD page is given it prints
out information in the form: "SCSI_VENDOR=<vendor>",
"SCSI_MODEL=<model>", and "SCSI_REVISION=<rev>", taken from the
standard inquiry. This may be useful for tools like udev(7) in
Linux.
-E, -x, --extended
prints the extended INQUIRY VPD page [0x86].
-h, --help
print out the usage message then exit. When used twice, after
the usage message, there is a list of available abbreviations
than can be given to the --page=PG option.
-H, --hex
rather than decode a standard INQUIRY response, a VPD page or
command support data; print out the response in hex and send the
output to stdout. Error messages and warnings are typically
output to stderr. When used twice with the ATA Information VPD
page [0x89] decodes the start of the response then outputs the
ATA IDENTIFY (PACKET) DEVICE response in hexadecimal bytes (not
16 bit words). When used three times with the ATA Information
VPD page [0x89] or the --ata option, this utility outputs the
ATA IDENTIFY (PACKET) DEVICE response in hexadecimal words suit-
able for input to 'hdparm --Istdin'. See note below.
To generate output suitable for placing in a file that can be
used by a later invocation with the --inhex=FN option, use the
'-HHHH' option (e.g. 'sg_inq -p di -HHHH /dev/sg3 >
dev_id.hex').
-i, --id
prints the device identification VPD page [0x83].
-I, --inhex=FN
FN is expected to be a file name (or '-' for stdin) which con-
tains ASCII hexadecimal or binary representing an INQUIRY (in-
cluding VPD page) response. This utility will then decode that
response. It is preferable to also supply the --page=PG option,
if not this utility will attempt to guess which VPD page (or
standard INQUIRY) that the response is associated with. The
hexadecimal should be arranged as 1 or 2 digits representing a
byte each of which is whitespace or comma separated. Anything
from and including a hash mark to the end of a line is ignored.
If the --raw option is also given then FN is treated as binary.
-l, --len=LEN
the number LEN is the "allocation length" field in the INQUIRY
cdb. This is the (maximum) length of the response returned by
the device. The default value of LEN is 0 which is interpreted
as: first request is for 36 bytes and if necessary execute an-
other INQUIRY if the "additional length" field in the response
indicates that more than 36 bytes is available.
If LEN is greater than 0 then only one INQUIRY command is per-
formed. This means that the Serial Number (obtained from the
Serial Number VPD pgae (0x80)) is not fetched and therefore not
printed. See the NOTES section below about "36 byte INQUIRYs".
-L, --long
this option causes more information to be decoded from the Iden-
tify command sent to a NVMe DEVICE.
-m, --maxlen=LEN
this option has the same action as the --len=LEN option above.
It has been added for compatibility with the sg_vpd, sg_modes
and sg_logs utilities.
-O, --old
Switch to older style options. Please use as first option on the
command line.
-o, --only
Do not attempt to additionally retrieve the serial number VPD
page (0x80) to enhance the output of a standard INQUIRY. So with
this option given and no others, this utility will send a stan-
dard INQUIRY SCSI command and decode its response. No other SCSI
commands will be sent to the DEVICE. Without this option an ad-
ditional SCSI command is sent: a (non-standard) SCSI INQUIRY to
fetch the Serial Number VPD page. However the Serial Number VPD
page is not mandatory (while the Device Identification page is
mandatory but a billion USB keys ignore that) and may cause nui-
sance error reports.
For NVMe devices only the Identify controller is performed, even
if the DEVICE includes a namespace identifier. For example in
FreeBSD given a DEVICE named /dev/nvme0ns1 then an Identify con-
troller is sent to /dev/nvme0 and nothing is sent to its "ns1"
(first namespace).
-p, --page=PG
the PG argument can be either a number of an abbreviation for a
VPD page. To enumerate the available abbreviations for VPD pages
use '-hh' or a bad abbreviation (e.g, '--page=xxx'). When the
--cmddt option is given (once) then PG is interpreted as an op-
code number (so VPD page abbreviations make little sense).
If PG is a negative number, then a standard INQUIRY is per-
formed. This can be used to override some guessing logic associ-
ated with the --inhex=FN option.
If PG is not found in the 'Supported VPD pages' VPD page (0x0)
then EDOM is returned. To bypass this check use the --force op-
tion.
-r, --raw
in the absence of --inhex=FN then the output response is in bi-
nary. The output should be piped to a file or another utility
when this option is used. The binary is sent to stdout, and er-
rors are sent to stderr.
If used with --inhex=FN then the contents of FN is treated as
binary.
-s, --vendor
output a standard INQUIRY response's vendor specific fields from
offset 36 to 55 in ASCII. When used twice (i.e. '-ss') also out-
put the vendor specific field from offset 96 in ASCII. This is
only done if the data passes some simple sanity checks.
-v, --verbose
increase level of verbosity. Can be used multiple times.
-V, --version
print out version string then exit.
-e, --vpd
set the Enable Vital Product Data (EVPD) bit (defaults to
clear(0)). Used in conjunction with the --page=PG option where
PG specifies the VPD page number to query. If the --page=PG is
not given then PG defaults to zero which is the "Supported VPD
pages" VPD page. A more up to date decoding of VPD pages can be
found in the sg_vpd(8) utility.
NOTES
Some devices with weak SCSI command set implementations lock up when
they receive commands they don't understand (and some lock up if they
receive response lengths that they don't expect). Such devices need to
be treated carefully, use the '--len=36' option. Without this option
this utility will issue an initial standard INQUIRY requesting 36 bytes
of response data. If the device indicates it could have supplied more
data then a second INQUIRY is issued to fetch the longer response. That
second command may lock up faulty devices.
ATA or ATAPI devices that use a SCSI to ATA Translation layer (see SAT
at www.t10.org) may support the SCSI ATA INFORMATION VPD page. This re-
turns the IDENTIFY (PACKET) DEVICE response amongst other things. The
ATA Information VPD page can be fetched with '--page=ai'.
In the INQUIRY standard response there is a 'MultiP' flag which is set
when the device has 2 or more ports. Some vendors use the preceding
vendor specific ('VS') bit to indicate which port is being accessed by
the INQUIRY command (0 -> relative port 1 (port "a"), 1 -> relative
port 2 (port "b")). When the 'MultiP' flag is set, the preceding vendor
specific bit is shown in parentheses. SPC-3 compliant devices should
use the device identification VPD page (0x83) to show which port is be-
ing used for access and the SCSI ports VPD page (0x88) to show all
available ports on the device.
In the 2.4 series of Linux kernels the DEVICE must be a SCSI generic
(sg) device. In the 2.6 series and later block devices (e.g. disks and
ATAPI DVDs) can also be specified. For example "sg_inq /dev/sda" will
work in the 2.6 series kernels. From lk 2.6.6 other SCSI "char" device
names may be used as well (e.g. "/dev/st0m").
The number of bytes output by --hex and --raw is 36 bytes or the number
given to --len=LEN (or --maxlen=LEN). That number is reduced if the
"resid" returned by the HBA indicates less bytes were sent back from
DEVICE.
The DEVICE is opened with a read-only flag (e.g. in Unix with the
O_RDONLY flag).
ATA DEVICES
There are two major types of ATA devices: non-packet devices (e.g. ATA
disks) and packet devices (ATAPI). The majority of ATAPI devices are
CD/DVD/BD drives in which the ATAPI transport carries the MMC set (i.e.
a SCSI command set). Further, both types of ATA devices can be con-
nected to a host computer via a "SCSI" (or some other) transport. When
an ATA disk is controlled via a SCSI (or non-ATA) transport then two
approaches are commonly used: tunnelling (e.g. STP in Serial Attached
SCSI (SAS)) or by emulating a SCSI device (e.g. with a SCSI to ATA
translation layer, see SAT at www.t10.org ). Even when the physical
transport to the host computer is ATA (especially in the case of SATA)
the operating system may choose to put a SAT layer in the driver
"stack" (e.g. libata in Linux).
The main identifying command for any SCSI device is an INQUIRY. The
corresponding command for an ATA non-packet device is IDENTIFY DEVICE
while for an ATA packet device it is IDENTIFY PACKET DEVICE.
When this utility is invoked for an ATAPI device (e.g. a CD/DVD/BD
drive with "sg_inq /dev/hdc") then a SCSI INQUIRY is sent to the device
and if it responds then the response to decoded and output and this
utility exits. To see the response for an ATA IDENTIFY PACKET DEVICE
command add the --ata option (e.g. "sg_inq --ata /dev/hdc).
This utility doesn't decode the response to an ATA IDENTIFY (PACKET)
DEVICE command, hdparm does a good job at that. The '-HHH' option has
been added for use with either the '--ata' or '--page=ai' option to
produce a format acceptable to "hdparm --Istdin". An example: 'sg_inq
--ata -HHH /dev/hdc | hdparm --Istdin'. See hdparm.
NVME DEVICES
Currently these device are typically SSDs (Solid State Disks) directly
connected to a PCIe connector or via a specialized connector such as a
M2 connector. Linux and FreeBSD treat NVMe storage devices as separate
from SCSI storage with device names like /dev/nvme0n1 (in Linux) and
/dev/nvme0ns1 (in FreeBSD). The NVM Express group has a document titled
"NVM Express: SCSI Translation Reference" which defines a partial "SCSI
to NVMe Translation Layer" often known by its acronym: SNTL.
On operating systems where it is supported by this package, this util-
ity will detect NVMe storage devices directly connected and send an
Identify controller NVMe Admin command and decode its response. A NVMe
controller is architecturally similar to a SCSI target device. If the
NVMe DEVICE indicates a namespace then an Identify namespace NVMe Admin
command is sent to that namespace and its response is decoded. Name-
spaces are numbered sequentially starting from 1. Namespaces are simi-
lar to SCSI Logical Units and their identifiers (nsid_s) can be thought
of as SCSI LUNs. In the Linux and FreeBSD example device names above
the "n1" and the "ns1" parts indicate nsid 1 . If no namespace is given
in the DEVICE then all namespaces found in the controller are sent
Identify namespace commands and the responses are decoded.
To get more details in the response use the --long option. To only get
the controller's Identify decoded use the --only option.
It is possible that even though the DEVICE presents as a NVMe device,
it has a SNTL and accepts SCSI commands. In this case to send a SCSI
INQUIRY command (and fetch its VPD pages) use 'sg_vpd -p sinq <dev>'
(or to get VPD pages: 'sg_vpd -p <vpd_page> <dev>').
EXIT STATUS
The exit status of sg_inq 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.
-36 only requests 36 bytes of response data for an INQUIRY. Further-
more even if the device indicates in its response it can supply
more data, a second (longer) INQUIRY is not performed. This is a
paranoid setting. Equivalent to '--len=36' in the OPTIONS sec-
tion.
-a fetch the ATA Information VPD page [0x89]. Equivalent to
'--page=ai' in the OPTIONS section. This page is defined in SAT
(see at www.t10.org).
-A Assume given DEVICE is an ATA or ATAPI device. Equivalent to
--ata in the OPTIONS section.
-b decodes the Block Limits VPD page [0xb0]. Equivalent to
'--page=bl' in the OPTIONS section. This page is defined in
SBC-2 (see www.t10.org) and later.
-B=0|1 equivalent to --block=0|1 in OPTIONS section.
-c set the Command Support Data (CmdDt) bit (defaults to clear(0)).
Used in conjunction with the -p=VPD_PG option to specify the
SCSI command opcode to query. Equivalent to --cmddt in the OP-
TIONS section.
-cl lists the command data for all supported commands (followed by
the command name) by looping through all 256 opcodes. This op-
tion uses the CmdDt bit which is now obsolete. See the sg_op-
codes(8) utility. Equivalent to '--cmddt --cmddt' in the OP-
TIONS section.
-d decodes depending on context. If -e option is given, or any op-
tion that implies -e (e.g. '-i' or '-p=80'), then this utility
attempts to decode the indicated VPD page. Otherwise the ver-
sion descriptors (if any) are listed following a standard IN-
QUIRY response. In the version descriptors sense, equivalent to
--descriptors in the OPTIONS section.
-e enable (i.e. sets) the Vital Product Data (EVPD) bit (defaults
to clear(0)). Used in conjunction with the -p=VPD_PG option to
specify the VPD page to fetch. If -p=VPD_PG is not given then
VPD page 0 (list supported VPD pages) is assumed.
-f Equivalent to --force in the OPTIONS section.
-h outputs INQUIRY response in hex rather than trying to decode it.
Equivalent to --hex in the OPTIONS section.
-H same action as -h. Equivalent to --hex in the OPTIONS section.
-i decodes the Device Identification VPD page [0x83]. Equivalent to
--id in the OPTIONS section. This page is made up of several
"designation descriptors". If -h is given then each descriptor
header is decoded and the identifier itself is output in hex. To
see the whole VPD 0x83 page response in hex use '-p=83 -h'.
-I=FN equivalent to --inhex=FN in the OPTIONS section.
-l=LEN equivalent to --len=LEN in the OPTIONS section.
-L equivalent to --long in the OPTIONS section.
-m decodes the Management network addresses VPD page [0x85]. Equiv-
alent to '--page=mna' in the OPTIONS section.
-M decodes the Mode page policy VPD page [0x87]. Equivalent to
'--page=mpp' in the OPTIONS section.
-N, --new
Switch to the newer style options.
-o equivalent to --only in the OPTIONS section.
-p=VPD_PG
used in conjunction with the -e or -c option. If neither given
then the -e option assumed. When the -e option is also given (or
assumed) then the argument to this option is the VPD page num-
ber. The argument is interpreted as hexadecimal and is expected
to be in the range 0 to ff inclusive. Only VPD page 0 is decoded
and it lists supported VPD pages and their names (if known). To
decode the mandatory device identification page (0x83) use the
-i option. A now obsolete usage is when the -c option is given
in which case the argument to this option is assumed to be a
command opcode number. Recent SCSI draft standards have moved
this facility to a separate command (see sg_opcodes(8)). De-
faults to 0 so if -e is given without this option then VPD page
0 is output.
-P decodes the Unit Path Report VPD page [0xc0] which is EMC spe-
cific. Equivalent to '--page=upr' in the OPTIONS section.
-r outputs the response in binary to stdout. Equivalent to --raw
in the OPTIONS section. Can be used twice (i.e. '-rr' (and
'-HHH' has same effect)) and if used with the -A or -a option
yields output with the same format as "cat /proc/ide/hd<x>/iden-
tify" so that it can then be piped to "hdparm --Istdin".
-s decodes the SCSI Ports VPD page [0x88]. Equivalent to
'--page=sp' in the OPTIONS section.
-u equivalent to '--export' in the OPTIONS section.
-v increase level of verbosity. Can be used multiple times.
-V print out version string then exit.
-x decodes the Extended INQUIRY data VPD [0x86] page. Equivalent
to '--page=ei' in the OPTIONS section.
-? output usage message and exit. 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 view the standard inquiry response use without options:
sg_inq /dev/sda
Some SCSI devices include version descriptors indicating the various
SCSI standards and drafts they support. They can be viewed with:
sg_inq -d /dev/sda
Modern SCSI devices include Vital Product Data (VPD)pages which can be
viewed with the SCSI INQUIRY command. To list the supported VPD pages
(but not their contents) try:
sg_inq -e /dev/sda
Some VPD pages can be read with the sg_inq utility but a newer utility
called sg_vpd specializes in showing their contents. The sdparm utility
can also be used to show the contents of VPD pages.
Further examples of sg_inq together with some typical output can be
found on http://sg.danny.cz/sg/sg3_utils.html web page.
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 © 2001-2021 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_opcodes(8), sg_vpd(8), sg_logs(8), sg_modes(8), sdparm(8), hd-
parm(8), sgdiag(scsirastools)
sg3_utils-1.46 March 2021 SG_INQ(8)
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