lsblk — list block devices
lsblk [options] [ device...
]
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 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.
−a,
−−allAlso list empty devices and RAM disk devices.
−b,
−−bytesPrint the SIZE column in bytes rather than in a human-readable format.
−D,
−−discardPrint information about the discarding capabilities (TRIM, UNMAP) for each device.
−d,
−−nodepsDo not print holder devices or slaves. For example, lsblk −−nodeps /dev/sda prints information about the sda device only.
−E,
−−dedup columnUse 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 listExclude 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,
−−fsOutput info about filesystems. This option is
equivalent to −o
NAME,FSTYPE,LABEL,UUID,FSAVAIL,FSUSE%,MOUNTPOINT.
The authoritative information about filesystems and
raids is provided by the blkid(8) command.
−h,
−−helpDisplay help text and exit.
−I,
−−include listInclude 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,
−−asciiUse ASCII characters for tree formatting.
−J,
−−jsonUse JSON output format. It's strongly recommended to
use −−output
and also −−tree
if necessary.
−l,
−−listProduce 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,
−−mergeGroup parents of sub-trees to provide more readable output for RAIDs and Multi-path devices. The tree-like output is required.
−m,
−−permsOutput info about device owner, group and mode. This
option is equivalent to −o
NAME,SIZE,OWNER,GROUP,MODE.
−n,
−−noheadingsDo not print a header line.
−o,
−−output listSpecify 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−allOutput all available columns.
−P,
−−pairsProduce 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,
−−pathsPrint full device paths.
−r,
−−rawProduce 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,
−−scsiOutput info about SCSI devices only. All partitions, slaves and holder devices are ignored.
−s,
−−inversePrint 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,
−−topologyOutput 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.
−V,
−−versionDisplay version information and exit.
−x,
−−sort columnSort 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,
−−zonedPrint the zone model for each device.
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.
0success
1failure
32none of specified devices found
64some specified devices found, some not found
LSBLK_DEBUG=allenables lsblk debug output.
LIBBLKID_DEBUG=allenables libblkid debug output.
LIBMOUNT_DEBUG=allenables libmount debug output.
LIBSMARTCOLS_DEBUG=allenables libsmartcols debug output.
LIBSMARTCOLS_DEBUG_PADDING=onuse visible padding characters. Requires enabled LIBSMARTCOLS_DEBUG.
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.