LSBLK(8) System Administration LSBLK(8)
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.
The command prints all block devices (except RAM disks) in a tree-like
format by default. Use lsblk --help to get a list of all available
columns.
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.
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.
-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.
-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, --noheadings
Do not print a header line.
-o, --output list
Specify which output columns to print. Use --help 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.
-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 <mbroz@redhat.com>, Karel Zak <kzak@redhat.com>
SEE ALSO
ls(1), blkid(8), findmnt(8)
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/>.
util-linux 2.38.1 2022-08-04 LSBLK(8)
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