lsblk(8) - phpMan

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 to gather information.

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 in
environments where a stable output is required.

OPTIONS
-a, --all
Also list empty devices. (By default they are skipped.)

-b, --bytes
Print the SIZE column in bytes rather than in a human-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, --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. The filter is applied to
the top-level devices only.

-f, --fs
Output info about filesystems. This option is equivalent to
-o NAME,FSTYPE,LABEL,MOUNTPOINT. The authoritative information about filesystems
and raids is provided by the blkid(8) command.

-h, --help
Print a 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.

-i, --ascii
Use ASCII characters for tree formatting.

-l, --list
Produce output in the form of a list.

-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 default list of columns may be extended if list is specified in the format
+list (e.g. lsblk -o +UUID).

-P, --pairs
Produce output in the form of key="value" pairs. All potentially unsafe characters
are hex-escaped (\x<code>).

-p, --paths
Print full device paths.

-r, --raw
Produce output in raw format. 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.

-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,WSAME.

-V, --version
Output version information and exit.

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 CON-
FIG_SYSFS was enabled at the time of the kernel build.

AUTHORS
Milan Broz <mbroz AT redhat.com>
Karel Zak <kzak AT redhat.com>

ENVIRONMENT
Setting LIBMOUNT_DEBUG=0xffff enables debug output.