Provided by: lsscsi_0.32-1build1_amd64 
NAME
lsscsi - list SCSI devices (or hosts), list NVMe devices
SYNOPSIS
lsscsi [--brief] [--classic] [--controllers] [--device] [--generic] [--help] [--hosts]
[--kname] [--list] [--long] [--long-unit] [--lunhex] [--no-nvme] [--pdt] [--protection]
[--protmode] [--scsi_id] [--size] [--sysfsroot=PATH] [--sz-lbs] [--transport] [--unit]
[--verbose] [--version] [--wwn] [H:C:T:L]
DESCRIPTION
Uses information in sysfs (Linux kernel series 2.6 and later) to list SCSI devices (or
hosts) currently attached to the system. Many non-SCSI storage devices (but not all) used
the SCSI subsystem in Linux. In lsscsi version 0.30 support was added to list NVMe
devices.
In single line per device (LU or NVMe namespace) mode, the default, each line starts with
a 4 element tuple surrounded by square brackets. For SCSI devices the first element 'H' is
the host number, the second element 'C' is the controller number, the third element 'T' is
the target number and the final element is the Logical Unit Number (LUN). All four are
integers. For NVMe namespaces see two paragraphs down. When the --hosts option is given
for SCSI devices the tuple is reduced to one element: the host number.
If a H:C:T:L tuple is given as an argument on the command line then it acts as a filter
and only devices that match it are listed. The colons don't have to be present, and '-',
'*', '?' or missing components at the end are interpreted as wildcards. The default is
'*:*:*:*' which means to match devices (i.e. Logical Units). Any filter string using '*'
of '?' should be surrounded by single or double quotes to stop shell expansions. If '-'
is used as a wildcard then the whole filter tuple should be prefixed by '-- ' to tell this
utility there are no more options on the command line to be interpreted. A leading '['
and trailing ']' are permitted ( e.g. '[1:0:0]' matches all LUNs on 1:0:0). May also be
used to filter --hosts in which case only the H is active and may be either a number or in
the form "host<n>" where <n> is a host number.
For NVMe devices and controllers almost all of the previous paragraph applies. The main
difference is that "N" appears in the 'H' (first) position. The 'C' position for NVMe is
the controller's Linux generated "char" device minor number which is the first number that
appears in a typical NVMe controller name, for example: "/dev/nvme2". The 'T' position for
NVMe is the "CNTLID" value. The final 'L' position is the NVMe namespace identifier which
is typically a sequential value starting at 1. The leading explicit "N" for NVMe devices
is converted internally into a large value (32,767) that should not interfere with any
Linux generated SCSI host number; it also means that the numeric sort used to show hosts
(controllers) and devices (LUs or logical units) will always place NVMe devices and
controllers after those that use the SCSI subsystem. To filter using a H:C:T:L argument
for NVMe controllers, "hostN", "hostN:<num>", "N" or "N:<num>" may be used; when no
"<num>" is given, only NVMe controllers will be listed (i.e. it lists no SCSI hosts
(HBAs)).
By default in this utility device node names (e.g. "/dev/sda" or "/dev/root_disk") are
obtained by noting the major and minor numbers for the listed device obtained from sysfs
(e.g. the contents of "/sys/block/sda/dev") and then looking for a match in the "/dev"
directory. This "match by major and minor" will allow devices that have been given a
different name by udev (for example) to be correctly reported by this utility.
In some situations it may be useful to see the device node name that Linux would produce
by default, so the --kname option is provided. An example of where this may be useful is
kernel error logs which tend to report disk error messages using the disk's default kernel
name.
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. Hyphenated long options can
also take underscore, and vice versa (e.g. --scsi_id or --scsi-id are acceptable).
-b, --brief
reduces one line per device output to the tuple and the primary device name. This
may simplify scripts that process the output of this utility. With the --generic
option it will show on each line the tuple (from which the bsg pass-through device
name can be deduced), the primary device name (which the block subsystem uses) and
the sg device name (also a pass-through).
When the --pdt option is used together with this option the SCSI Peripheral Device
Type (PDT) is displayed in hex (with a leading "0x") between the tuple and the
primary device name. For NVMe namespaces "0x0" is displayed (for a disk or direct
access device).
-c, --classic
The output is similar to that obtained from 'cat /proc/scsi/scsi'
-C, --controllers
Lists NVMe controllers and SCSI hosts. This is a synonym for the --hosts option.
-d, --device
After outputting the (probable) SCSI device name the device node major and minor
numbers are shown in brackets (e.g. "/dev/sda[8:0]").
-g, --generic
Output the SCSI generic device file name. Note that if the sg driver is a module it
may need to be loaded otherwise '-' may appear.
NVMe does not have generic (char) devices in the same sense as SCSI. Instead NVMe
Admin, NVM (i.e. block type commands such as Read and Write) and MI (Management
Interface (e.g. to an enclosure)) commands are all sent to the containing
controller whose device name is shown when the --hosts option is used.
To unclutter the single line per device mode the --brief option combined with this
option should help.
-h, --help
Output the usage message and exit.
-H, --hosts
List the SCSI hosts and NVMe controllers currently attached to the system. If this
option is not given (and the --controllers option is not given) then SCSI devices
(logical units (LUs)) followed by NVMe devices (namespaces) are listed.
-k, --kname
Use Linux default algorithm for naming devices (e.g. block major 8, minor 0 is
"/dev/sda") rather than the "match by major and minor" in the "/dev" directory as
discussed above.
-L, --list
Output additional information in <attribute_name>=<value> pairs, one pair per line
preceded by two spaces. This option has the same effect as '-lll'.
-l, --long
Output additional information for each SCSI device (host). Can be used multiple
times for more output in which case the shorter option form is more convenient
(e.g. '-lll'). When used three times (i.e. '-lll') outputs SCSI device (host)
attributes one per line; preceded by two spaces; in the form
"<attribute_name>=<value>".
-U, --long-unit
Output logical unit name in full, if available. It replaces the normal vendor,
product and revision strings given in the single logical unit per line mode. If no
logical unit name is found "none" is printed. If the logical unit name is long
(e.g. a UUID) then following fields are pushed further to the right as required.
This option is functionally equivalent to the '-uuu' option.
If the option is used twice (e.g. '-UU') then EUI, NAA, UUID and T10 vendor ID
formats are prefixed by "eui.", "naa.", "uuid." and "t10." respectively. Note that
SCSI name format used by iSCSI should already be prefixed by 'iqn.'. Using the
'--unit' option 4 or more times (e.g. '-uuuu') will have the same action as '-UU'.
--long_unit is also an acceptable form when invoking this option.
-x, --lunhex
when this option is used once the LUN in the tuple (at the start of each device
line) is shown in "T10" format which is up to 16 hexadecimal digits. It is prefixed
by "0x" to distinguish the LUN from the decimal value shown in the absence of this
option. Also hierarchal LUNs are shown with a "_" character separating the levels.
For example the two level LUN: 0x0355006600000000 will appear as 0x0355_0066. If
this option is given twice (e.g. using the short form: '-xx') then the full 16
hexadecimal digits are shown for each LUN, prefixed by "0x".
For NVMe, the namespace identifier (nsid) is shown in the "L" position. The nsid is
a 32 bit unsigned quantities with 0x0 and 0xffffffff reserved. Without this
option, the nsid is shown in decimal. When this option is used once the nsid is
output in hex with a lead 0x and with up to 3 leading zeros. When this option is
used twice the nsid is output in hex with up to 7 leading zeros.
-N, --no-nvme
this option excludes NVMe devices and controllers for the output. This option may
be needed to stop NVMe device output interfering with specific format output like
that produced when the --classic option is used.
To only show NVMe devices, use 'lsscsi N', to only show NVMe controllers, use
'lsscsi -H N'.
-D, --pdt
this option displays the SCSI Peripheral Device Type (PDT) in hex preceded by "0x".
For NVME namespaces "0x0' is displayed which corresponds to a disk ("Direct Access
Device" or SSD). In single line output this hex PDT replaces the device type
abbreviation (e.g. "0x0 " replaces "disk ") and appears after the tuple.
-p, --protection
Output target (DIF) and initiator (DIX) protection types.
-P, --protmode
Output effective protection information mode for each disk device.
-i, --scsi_id
outputs the udev derived matching id found in /dev/disk/by-id/scsi* . This is only
for disk (and disk like) devices. If no match is found then "dm-uuid-mpath*" and
"usb*" are searched in the same directory. If there is still no match then the
/sys/class/block/<disk>/holders directory is searched. The matching id is printed
following the device name (e.g. /dev/sdc) and if there is no match "-" is output.
Note that only disk (like) devices are matched by this option; so, for example, a
SCSI enclosure will have an identifier of '-'.
Prior to revision 164 the first match in /dev/disk/by-id/scsi* was printed. A
change was added at that point to check for identifiers in a specific order as some
are considered "stronger" than others. See the ORDER OF SCSI IDENTIFIERS section
below.
-s, --size
Print disk capacity in human readable form. When given once, normal base 10 SI
units are used as a prefix for 'B' which is bytes (aka octets). For example MB, GB
and TB stand for 10^6, 10^9 and 10^12 bytes respectively. When given twice, IEC
80000-3 prefixes for 'B' are used; for example MiB, GiB and TiB stand for 2^20,
2^30 and 2^40 bytes respectively. The output is rounded to 3 or less significant
figures in order to fit on a single line. It will also output the size of RBC
devices, CD/DVD media and host managed ZBC disks. Host aware ZBC disks have their
"peripheral device type" set to 0 (the same as normal disks) so their size is
output.
If given three times (short form is the more convenient: '-sss') then the disk
capacity as a logical block count is given. This is an exact figure in decimal
reported by the storage device at discovery. Discovery is typically just after boot
time, or when it was last attached if the storage device is removable.
To unclutter the single line per device mode the --brief option combined with this
option should help.
-y, --sysfsroot=PATH
assumes sysfs is mounted at PATH instead of the default '/sys' . If this option is
given PATH should be an absolute path (i.e. start with '/').
-S, --sz-lbs
Print disk capacity as a number of logical blocks (which is the same as '-sss').
When used twice a comma is added followed by the logical block size in bytes. It
should be a number like 512 or 4096.
If the logical block size cannot be found (e.g. because the version of Linux
predates the /sys/block/<dev_name>/queue directory) then the number of 512 byte
blocks followed comma and then '512' is output irrespective of what the true
logical block size of the device is. This special case action occurs whether this
option is given one or more times.
To unclutter the single line per device mode the --brief option combined with this
option should help.
-t, --transport
Output transport information. This will be target related information or, if
--hosts is given, initiator related information. When used without --list, a name
or identifier (or both) are output on a single line, usually prefixed by the type
of transport. For devices this information replaces the normal vendor, product and
revision strings. When the --list option is also given then additionally multiple
lines of attribute_name=value pairs are output, each indented by two spaces. See
the section on transports below.
-u, --unit
Output logical unit name, if available. If this option is given once or twice, then
the 30 character field where the vendor, product and revision strings are usually
placed is expanded to 32 characters and replaced by the logical unit name. If no
logical unit name is found "none" is printed. The first found of the NAA, EUI-64
or SCSI name string is output unless a SCSI name string is found and the associated
target port indicates the iSCSI protocol, in which case the SCSI name string is
preferred. Finally if there is no match on the above and a T10 Vendor ID descriptor
is found then it is used.
If the name cannot fit in the 32 character field then it is truncated to the right
and a trailing '_' character is used to alert the reader to the truncation. The 32
character width is chosen since that is large enough to hold 16 byte NAA or EUI-64
identifiers. However SCSI name strings as used by iSCSI can be larger than that.
If this option is used twice then this field is also 32 character wide. If the
logical unit name cannot fit then it will be truncated to the left and a leading
'_' character is used to alert the reader to the truncation.
If this option is used three times the whole logical unit name is output, followed
by several spaces.
In order for this option to work, it needs a Linux kernel from and including 3.15 .
It accesses the sysfs vpd_pg83 file for the device in question. Old SCSI and ATA
(SATA) equipment may not provide this information. If it is provided by ATA (SATA)
then it will be the WWN.
-v, --verbose
outputs directory names where information is found. Use multiple times for more
output.
-V, --version
outputs version information then exits. If used once outputs to stderr; if used
twice outputs to stdout and shortens the date to yyyymmdd numeric format. The first
number in the version string is the release number.
-w, --wwn
outputs the WWN for disks instead of manufacturer, model and revision (or instead
of transport information). The World Wide Name (WWN) is typically 64 bits long (16
hex digits) but could be up to 128 bits long. To indicate the WWN is hexadecimal,
it is prefixed by "0x". The ATA/SATA WWN is referred to as LU name in SCSI jargon;
hence this option is more or less superseded by the --unit and --long-unit options.
TRANSPORTS
This utility lists SCSI devices which are known as logical units (LU) in the SCSI
Architecture Model (ref: SAM-5 at https://www.t10.org) or hosts when the --hosts option is
given. A host is called an initiator in SAM-5. A SCSI command travels out via an
initiator, across some transport to a target and then onwards to a logical unit. A target
device may contain several logical units. A target device has one or more ports that can
be viewed as transport end points. Each FC and SAS disk is a single target that has two
ports and contains one logical unit. If both target ports on a FC or SAS disk are
connected and visible to a machine, then lsscsi will show two entries. Initiators (i.e.
hosts) also have one or more ports and some HBAs in Linux have a host entry per initiator
port while others have a host entry per initiator device.
When the --transport option is given for devices (i.e. --hosts not given) then most of
the information produced by lsscsi is associated with the target, or more precisely: the
target port, through which SCSI commands pass that access a logical unit.
Typically this utility provides one line of output per "device" or host. Significantly
more information can be obtained by adding the --list option. When used together with the
--transport option, after the summary line, multiple lines of transport specific
information in the form "<attribute_name>=<value>" are output, each indented by two
spaces. Using a filter argument will reduce the volume of output if a lot of devices or
hosts are present.
The transports that are currently recognized are: IEEE 1394, ATA, FC, iSCSI, SAS, SATA,
SPI, SRP and USB.
For IEEE 1394 (a.k.a. Firewire and "SBP" when storage is involved), the EUI-64 based
target port name is output when --transport is given, in the absence of the --hosts
option. When the --hosts option is given then the EUI-64 initiator port name is output.
Output on the summary line specific to the IEEE 1394 transport is prefixed by "sbp:".
To detect ATA and SATA devices a crude check is performed on the driver name (after the
checks for other transports are exhausted). Based on the driver name either the ATA or
SATA transport type is chosen. Output on the summary line is either "ata:" or "sata:". A
search is made for an associated vpd_pg83 file in sysfs, if found it may contain the
device's WWN which is output if present. The WWN will not appear in Linux kernels before
3.15 and with old PATA and SATA devices. Most device and hosts flagged as "ata:" will use
the parallel ATA transport (PATA). For SATA devices that are attached via a SAS expander,
see the SAS paragraph below.
For Fibre Channel (FC) the port name and port identifier are output when --transport is
given. In the absence of the --hosts option these ids will be for the target port
associated with the device (logical unit) being listed. When the --hosts option is given
then the ids are for the initiator port used by the host. Output on the summary line
specific to the FC transport is prefixed by "fc:". If FCoE (over Ethernet) is detected
the prefix is changed to "fcoe:".
For iSCSI the target port name is output when --transport is given, in the absence of the
--hosts option. This is made up of the iSCSI name and the target portal group tag. Since
the iSCSI name starts with "iqn" no further prefix is used. When the --hosts option is
given then only "iscsi:" is output on the summary line.
For Serial Attached SCSI the SAS address of the target port (or initiator port if --hosts
option is also given) is output. This will be a naa-5 address. For SAS HBAs and SAS
targets (such as SAS disks and tape drives) the SAS address will be world wide unique. For
SATA disks attached to a SAS expander, the expander provides the SAS address by adding a
non zero value to its (i.e. the expander's) SAS address (e.g. expander_sas_address +
phy_id + 1). SATA disks directly attached to SAS HBAs seem to have an indeterminate SAS
address. Output on the summary line specific to the SAS transport is prefixed by "sas:".
For SATA devices, see the paragraph above on ATA devices. As noted in the previous
paragraph, SATA devices attached to SAS expanders will display a manufactured SAS
transport address (manufactured by the expander) rather than the SATA device's WWN.
For the SCSI Parallel Interface (SPI) the target port identifier (usually a number between
0 and 15 inclusive) is output when --transport is given, in the absence of the --hosts
option. When the --hosts option is given then only "spi:" is output on the summary line.
For the PCIe transport (a.k.a. PCI Express) there at two possible storage types: NVMe and
SOP/PQI (SCSI over PCIe). There are very few examples of the latter currently so this
utility concentrates on NVMe. NVMe uses its own command set and not SCSI but has many
things in common. Rather than re-invent everything currently in use that SCSI has
accumulated over nearly 40 years, NVMe is beginning to use some parts of SCSI. A recent
example is the SES-3 standard for enclosure management which has been adopted by NVMe. In
SCSI a SES device is a logical unit with a peripheral device type (PDT) of 0xd (for
enclosure) so it will appear when the lsscsi utility is invoked without any options. In
NVMe is seems that an enclosure with appear as attached to the management interface (MI)
of a NVMe controller. This means it should appear when "lsscsi --hosts" is invoked. It is
unclear whether such a NVMe controller can have any storage namespaces associated with it.
The sg_ses utility (in the sg3_utils package) can then be given that NVMe controller's
device name (e.g. /dev/nmve1).
When the --transport option is given, after "pcie" the NVMe controller's subsystem vendor
id and device id are output, separated by a colon (e.g. "pcie 0x8086:0x390a").
For the SCSI RDMA Protocol (SRP) the IB (InfiniBand) port's GUID is given. As an example,
it has a form like this: 0002:c903:00fa:abcd .
When a USB transport is detected, the summary line will contain "usb:" followed by a USB
device name. The USB device name has the form "<b>-<p1>[.<p2>[.<p3>]]:<c>.<i>" where <b>
is the USB bus number, <p1> is the port on the host. <p2> is a port on a host connected
hub, if present. If needed <p3> is a USB hub port closer to the USB storage device. <c>
refers to the configuration number while <i> is the interface number. There is a separate
SCSI host for each USB (SCSI) target. A USB SCSI target may contain multiple logical
units. Thus the same "usb: <device_name>" string appears for a USB SCSI host and all
logical units that belong to the USB SCSI target associated with that USB SCSI host.
LUNS
For historical reasons and as used by several other Unix based Operating Systems, Linux
uses a tuple of integers to describe (a path to) a SCSI device (also know as a Logical
Unit (LU)). The last element of that tuple is the so-called Logical Unit Number (LUN). And
originally in SCSI a LUN was an integer, at first 3 bits long, then 8 then 16 bits. SCSI
LUNs today (SAM-5 section 4.7) are 64 bits but SCSI standards now consider a LUN to be an
array of 8 bytes.
Up until 2013, Linux mapped SCSI LUNs to a 32 bit integer by taking the first 4 bytes of
the SCSI LUN and ignoring the last 4 bytes. Linux treated the first two bytes of the SCSI
LUN as a unit (a word) and it became the least significant 16 bits in the Linux LUN
integer. The next two bytes of the SCSI LUN became the upper 16 bits in the Linux LUN
integer. The rationale for this was to keep commonly used LUNs small Linux LUN integers.
The most common LUN (by far) in SCSI LUN (hex) notation is 00 00 00 00 00 00 00 00 and
this becomes the Linux LUN integer 0. The next most common LUN is 00 01 00 00 00 00 00 00
and this becomes the Linux LUN integer 1.
In 2013 it is proposed to increase Linux LUNs to a 64 bit integer by extending the mapping
outlined above. In this case all information that is possible to represent in a SCSI LUN
is mapped a Linux LUN (64 bit) integer. And the mapping can be reversed without losing
information.
This version of the utility supports both 32 and 64 bit Linux LUN integers. By default
the LUN shown at the end of the tuple commencing each line is a Linux LUN as a decimal
integer. When the --lunhex option is given then the LUN is in SCSI LUN format with the 8
bytes run together, with the output in hexadecimal and prefixed by '0x'. The LUN is
decoded according to SAM-5's description and trailing zeros (i.e. digits to the right) are
not shown. So LUN 0 (i.e. 00 00 00 00 00 00 00 00) is shown as 0x0000 and LUN 65 (i.e. 00
41 00 00 00 00 00 00) is shown as 0x0041. If the --lunhex option is given twice then the
full 64 bits (i.e. 16 hexadecimal digits) are shown.
If the --lunhex option is not given on the command line then the environment variable
LSSCSI_LUNHEX_OPT is checked. If LSSCSI_LUNHEX_OPT is present then its associated value
becomes the number of times the --lunhex is set internally. So, for example,
'LSSCSI_LUNHEX_OPT=2 lsscsi' and 'lsscsi -xx' are equivalent.
ORDER OF SCSI IDENTIFIERS
This section only applies to the --scsi_id option and only for disk like devices (e.g. not
tapes nor enclosures). There are potentially several SCSI identifiers and from revision
164 they are checked in the following order and only the first found is output.
The SCSI identifier preference order is:
3 : NAA based (Network address Authority)
2 : EUI-64 based
8 : SCSI name string (e.g. iSCSI: iqn.1998-01.com.zzware.iscsi:name1)
S : serial number from SCSI VPD page 0x80
1 : T10 Vendor Identifier
0 : Vendor Specific
Those numbers prefixing each entry are the SCSI 'Designator Types' found in the definition
of the Device Identification VPD page (0x83) in SPC/-3, SPC/-4 and SPC/-5. The 'S' of
course if not a number and it refers to a different VPD page: the Serial Number VPD page
(0x80).
There is a more general --wwn option that should apply to almost all devices. The term
"WWN" (world-wide name) comes from the ATA and NVMe standards and corresponds to the
"Logical Unit (LU) name" in SCSI. The LU name in SCSI tends to change by transport. For
SAS the LU name is the LU's NAA identifier.
Plus there the --unit and the --long-unit options that may be helpful in uniquely
identifying storage devices.
EXAMPLES
Information about this utility including examples can also be found at:
https://sg.danny.cz/scsi/lsscsi.html .
NOTES
Information for this command is derived from the sysfs file system, which is assumed to be
mounted at /sys unless specified otherwise by the user. SCSI (pseudo) devices that have
been detected by the SCSI mid level will be listed even if the required upper level
drivers (i.e. sd, sr, st, osst or ch) have not been loaded. If the appropriate upper level
driver has not been loaded then the device file name will appear as '-' rather than
something like '/dev/st0'. Note that some devices (e.g. scanners and medium changers) do
not have a primary upper level driver and can only be accessed via a SCSI generic (sg)
device name.
Generic SCSI devices can also be accessed via the bsg driver in Linux. By default, the
bsg driver's device node names are of the form '/dev/bsg/H:C:T:L'. So, for example, the
SCSI device shown by this utility on a line starting with the tuple '6:0:1:2' could be
accessed via the bsg driver with the '/dev/bsg/6:0:1:2' device node name.
lsscsi version 0.21 or later is required to correctly display SCSI devices in Linux kernel
2.6.26 (and possibly later) when the CONFIG_SYSFS_DEPRECATED_V2 kernel option is not
defined.
AUTHOR
Written by Doug Gilbert
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright © 2003-2021 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.
SEE ALSO
lspci lsusb lsblk