Linux磁盘管理指令lsblk-man帮助手册

Linux磁盘管理指令-man帮助手册

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, --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, 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.

-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 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>). The key (variable name) will be modified to contain
only characters allowed for a shell variable identifiers, for example, MIN_IO
and FSUSE_PCT instead of MIN-IO and FSUSE%.

-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.

-V, --version
Display version information 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.

-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.

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 <[email protected]>, Karel Zak <[email protected]>