sg_inq - issue SCSI INQUIRY command and/or decode its response
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] [--verbose]
[--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
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 section.
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 information 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
INCITS 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.
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 INQUIRY command and
use either the ATA IDENTIFY DEVICE command (for non-packet devices) or the
ATA IDENTIFY PACKET DEVICE command. 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 default value depends on the operating system and the type of
DEVICE 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_opcodes(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) followed 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
suitable 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 contains
ASCII hexadecimal or binary representing an INQUIRY (including 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 another 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 performed.
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 Identify
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 standard INQUIRY SCSI command and
decode its response. No other SCSI commands will be sent to the
DEVICE. Without this option an additional 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 nuisance 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 controller 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 opcode number (so VPD
page abbreviations make little sense).
If PG is a negative number, then a standard INQUIRY is performed.
This can be used to override some guessing logic associated 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 option.
- -r, --raw
- in the absence of --inhex=FN then the output response is in binary.
The output should be piped to a file or another utility when this option
is used. The binary is sent to stdout, and errors 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 output 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.
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
returns 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 being 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).
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 connected 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.
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
utility 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. Namespaces
are numbered sequentially starting from 1. Namespaces are similar 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>').
The exit status of sg_inq is 0 when it is successful. Otherwise see the
sg3_utils(8) man page.
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. Furthermore 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 section.
- -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 OPTIONS section.
- -cl
- lists the command data for all supported commands (followed by the command
name) by looping through all 256 opcodes. This option uses the CmdDt bit
which is now obsolete. See the sg_opcodes(8) utility. Equivalent to
'--cmddt --cmddt' in the OPTIONS section.
- -d
- decodes depending on context. If -e option is given, or any option
that implies -e (e.g. '-i' or '-p=80'), then this utility attempts
to decode the indicated VPD page. Otherwise the version descriptors (if
any) are listed following a standard INQUIRY 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]. Equivalent 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
number. 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)). Defaults 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 specific.
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>/identify" 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.
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.
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 environment variable is equivalent to using
--old (or -O) as the first command line option.
Written by Douglas Gilbert
Report bugs to <dgilbert at interlog dot com>.
Copyright © 2001-2018 Douglas Gilbert
This software is distributed under the GPL version 2. There is NO warranty; not
even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
sg_opcodes(8), sg_vpd(8), sg_logs(8), sg_modes(8), sdparm(8), hdparm(8),
sgdiag(scsirastools)