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 de-
vices. The lsblk command reads the sysfs filesystem and udev db to
gather information. If the udev db is not available or lsblk is com-
piled without udev support than 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.
OPTIONS
-a, --all
Also list empty devices and RAM disk devices.
-b, --bytes
Print the SIZE column in bytes rather than in a human-readable
format.
-D, --discard
Print information about the discarding capabilities (TRIM, UN-
MAP) 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 ma-
jor 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,LABEL,UUID,FSAVAIL,FSUSE%,MOUNTPOINT. The au-
thoritative information about filesystems and raids is provided
by the blkid(8) command.
-h, --help
Display help text and exit.
-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 hier-
archy 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 --out-
put and also --tree if necessary.
-l, --list
Produce output in the form of a list. The output does not pro-
vide 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 out-
put. 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
characters are hex-escaped (\x<code>).
-p, --paths
Print full device paths.
-r, --raw
Produce output in raw format. The output lines are still or-
dered 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 re-
quested 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 equiva-
lent to -o NAME,ALIGNMENT,MIN-IO,OPT-IO,PHY-SEC,LOG-
SEC,ROTA,SCHED,RQ-SIZE,RA,WSAME.
-V, --version
Display version information and exit.
-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.
-z, --zoned
Print the zone model 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.
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 ma-
jor: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.
RETURN CODES
0 success
1 failure
32 none of specified devices found
64 some specified devices found, some not found
AUTHORS
Milan Broz <mbroz@redhat.com>
Karel Zak <kzak@redhat.com>
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. Requires enabled LIBSMART-
COLS_DEBUG.
SEE ALSO
ls(1), blkid(8), findmnt(8)
AVAILABILITY
The lsblk command is part of the util-linux package and is available
from https://www.kernel.org/pub/linux/utils/util-linux/.
util-linux February 2013 LSBLK(8)