Provided by: util-linux_2.40.2-1ubuntu2_amd64 
NAME
lsblk - list block devices
SYNOPSIS
lsblk [options] [device...]
DESCRIPTION
lsblk lists information about all available or the specified block devices. The lsblk
command reads the sysfs filesystem and udev db to gather information. If the udev db is
not available or lsblk is compiled without udev support, then it tries to read LABELs,
UUIDs and filesystem types from the block device. In this case root permissions are
necessary.
By default, the command prints all block devices (except RAM disks) in a tree-like format.
The same device can be repeated in the tree if it relates to other devices. The --merge
option is recommended for more complicated setups to gather groups of devices and describe
complex N:M relationships.
The tree-like output (or children[] array in the JSON output) is enabled only if NAME
column it present in the output or when --tree command line option is used. See also
--nodeps and --list to control the tree formatting.
The default output, as well as the default output from options like --fs and --topology,
is subject to change. So whenever possible, you should avoid using default outputs in your
scripts. Always explicitly define expected columns by using --output columns-list and
--list in environments where a stable output is required.
Use lsblk --list-columns to get a list of all available columns.
Note that lsblk might be executed in time when udev does not have all information about
recently added or modified devices yet. In this case it is recommended to use udevadm
settle before lsblk to synchronize with udev.
The relationship between block devices and filesystems is not always one-to-one. The
filesystem may use more block devices, or the same filesystem may be accessible by more
paths. This is the reason why lsblk provides MOUNTPOINT and MOUNTPOINTS (pl.) columns. The
column MOUNTPOINT displays only one mount point (usually the last mounted instance of the
filesystem), and the column MOUNTPOINTS displays by multi-line cell all mount points
associated with the device.
OPTIONS
-A, --noempty
Don’t print empty devices.
-a, --all
Disable all built-in filters and list all empty devices and RAM disk devices too.
-b, --bytes
Print the sizes in bytes rather than in a human-readable format.
By default, the unit, sizes are expressed in, is byte, and unit prefixes are in power
of 2^10 (1024). Abbreviations of symbols are exhibited truncated in order to reach a
better readability, by exhibiting alone the first letter of them; examples: "1 KiB"
and "1 MiB" are respectively exhibited as "1 K" and "1 M", then omitting on purpose
the mention "iB", which is part of these abbreviations.
-H, --list-columns
List the available columns, use with --json or --raw to get output in machine-readable
format.
-D, --discard
Print information about the discarding capabilities (TRIM, UNMAP) for each device.
-d, --nodeps
Do not print holder devices or slaves. For example, lsblk --nodeps /dev/sda prints
information about the sda device only.
-E, --dedup column
Use column as a de-duplication key to de-duplicate output tree. If the key is not
available for the device, or the device is a partition and parental whole-disk device
provides the same key than the device is always printed.
The usual use case is to de-duplicate output on system multi-path devices, for example
by -E WWN.
-e, --exclude list
Exclude the devices specified by the comma-separated list of major device numbers.
Note that RAM disks (major=1) are excluded by default if --all is not specified. The
filter is applied to the top-level devices only. This may be confusing for --list
output format where hierarchy of the devices is not obvious.
-f, --fs
Output info about filesystems. This option is equivalent to -o
NAME,FSTYPE,FSVER,LABEL,UUID,FSAVAIL,FSUSE%,MOUNTPOINTS. The authoritative information
about filesystems and raids is provided by the blkid(8) command.
-I, --include list
Include devices specified by the comma-separated list of major device numbers. The
filter is applied to the top-level devices only. This may be confusing for --list
output format where hierarchy of the devices is not obvious.
-i, --ascii
Use ASCII characters for tree formatting.
-J, --json
Use JSON output format. It’s strongly recommended to use --output and also --tree if
necessary. Note that children[] is used only if NAME column or --tree is used.
-l, --list
Produce output in the form of a list. The output does not provide information about
relationships between devices and since version 2.34 every device is printed only once
if --pairs or --raw not specified (the parsable outputs are maintained in backwardly
compatible way).
-M, --merge
Group parents of sub-trees to provide more readable output for RAIDs and Multi-path
devices. The tree-like output is required.
-m, --perms
Output info about device owner, group and mode. This option is equivalent to -o
NAME,SIZE,OWNER,GROUP,MODE.
-N, --nvme
Output info about NVMe devices only.
-v, --virtio
Output info about virtio devices only.
-n, --noheadings
Do not print a header line.
-o, --output list
Specify which output columns to print. Use --list-columns to get a list of all
supported columns. The columns may affect tree-like output. The default is to use tree
for the column 'NAME' (see also --tree).
The default list of columns may be extended if list is specified in the format +list
(e.g., lsblk -o +UUID).
-O, --output-all
Output all available columns.
-P, --pairs
Produce output in the form of key="value" pairs. The output lines are still ordered by
dependencies. All potentially unsafe value characters are hex-escaped (\x<code>). See
also option --shell.
-p, --paths
Print full device paths.
-Q, --filter expr
Print only the devices that meet the conditions specified by the expr. The filter is
assessed prior to lsblk collecting data for all output columns. Only the necessary
data for the lazy evaluation of the expression is retrieved from the system. This
approach can enhance performance when compared to post-filtering, as commonly done by
tools such as grep(1).
This feature is EXPERIMENTAL. See also scols-filter(5). For example exclude sda and
sdb, but print everything else ('!~' is a negative regular expression matching
operator):
lsblk --filter 'NAME !~ "sd[ab]"'
--highlight expr
Colorize lines matching the expression. This feature is EXPERIMENTAL. See also
scols-filter(5).
--ct name [: param [: function ]]
Define a custom counter. The counters are printed after the standard output. The name
is the custom name of the counter, the optional param is the name of the column to be
used for the counter, and the optional function specifies the aggregation function,
supported functions are: count, min, max, or sum. The default is count.
If the param is not specified, then the counter counts the number of lines. This
feature is EXPERIMENTAL. See also --ct-filter.
For example, --ct MyCounter:SIZE:sum will count the summary for SIZE from all lines;
and to count the number of SATA disks, it is possible to use:
lsblk --ct-filter 'TYPE=="disk" && TRAN=="sata"' --ct "Number of SATA devices"
--ct-filter expr
Define a restriction for the next counter. This feature is EXPERIMENTAL. See also --ct
and scols-filter(5). For example, aggregate sizes by device type:
lsblk --ct-filter 'TYPE=="part"' --ct Partitions:SIZE:sum \
--ct-filter 'TYPE=="disk"' --ct WholeDisks:SIZE:sum
-r, --raw
Produce output in raw format. The output lines are still ordered by dependencies. All
potentially unsafe characters are hex-escaped (\x<code>) in the NAME, KNAME, LABEL,
PARTLABEL and MOUNTPOINT columns.
-S, --scsi
Output info about SCSI devices only. All partitions, slaves and holder devices are
ignored.
-s, --inverse
Print dependencies in inverse order. If the --list output is requested then the lines
are still ordered by dependencies.
-T, --tree[=column]
Force tree-like output format. If column is specified, then a tree is printed in the
column. The default is NAME column.
-t, --topology
Output info about block-device topology. This option is equivalent to
-o NAME,ALIGNMENT,MIN-IO,OPT-IO,PHY-SEC,LOG-SEC,ROTA,SCHED,RQ-SIZE,RA,WSAME.
-h, --help
Display help text and exit.
-V, --version
Print version and exit.
-w, --width number
Specifies output width as a number of characters. The default is the number of the
terminal columns, and if not executed on a terminal, then output width is not
restricted at all by default. This option also forces lsblk to assume that terminal
control characters and unsafe characters are not allowed. The expected use-case is for
example when lsblk is used by the watch(1) command.
-x, --sort column
Sort output lines by column. This option enables --list output format by default. It
is possible to use the option --tree to force tree-like output and than the tree
branches are sorted by the column.
-y, --shell
The column name will be modified to contain only characters allowed for shell variable
identifiers, for example, MIN_IO and FSUSE_PCT instead of MIN-IO and FSUSE%. This is
usable, for example, with --pairs. Note that this feature has been automatically
enabled for --pairs in version 2.37, but due to compatibility issues, now it’s
necessary to request this behavior by --shell.
-z, --zoned
Print the zone related information for each device.
--sysroot directory
Gather data for a Linux instance other than the instance from which the lsblk command
is issued. The specified directory is the system root of the Linux instance to be
inspected. The real device nodes in the target directory can be replaced by text files
with udev attributes.
EXIT STATUS
0
success
1
failure
32
none of specified devices found
64
some specified devices found, some not found
ENVIRONMENT
LSBLK_DEBUG=all
enables lsblk debug output.
LIBBLKID_DEBUG=all
enables libblkid debug output.
LIBMOUNT_DEBUG=all
enables libmount debug output.
LIBSMARTCOLS_DEBUG=all
enables libsmartcols debug output.
LIBSMARTCOLS_DEBUG_PADDING=on
use visible padding characters.
NOTES
For partitions, some information (e.g., queue attributes) is inherited from the parent
device.
The lsblk command needs to be able to look up each block device by major:minor numbers,
which is done by using /sys/dev/block. This sysfs block directory appeared in kernel
2.6.27 (October 2008). In case of problems with a new enough kernel, check that
CONFIG_SYSFS was enabled at the time of the kernel build.
AUTHORS
Milan Broz <gmazyland@gmail.com>, Karel Zak <kzak@redhat.com>
SEE ALSO
blkid(8), findmnt(8) ls(1), scols-filter(5)
REPORTING BUGS
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
AVAILABILITY
The lsblk command is part of the util-linux package which can be downloaded from Linux
Kernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.