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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | ENVIRONMENT | NOTES | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY |
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LSBLK(8) System Administration LSBLK(8)
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, then it tries to read
LABELs, UUIDs and filesystem types from the block device. In this
case root permissions are necessary.
By default, the command prints all block devices (except RAM
disks) in a tree-like format. The same device can be repeated in
the tree if it relates to other devices. The --merge option is
recommended for more complicated setups to gather groups of
devices and describe complex N:M relationships.
The tree-like output (or children[] array in the JSON output) is
enabled only if NAME column it present in the output or when
--tree command line option is used. See also --nodeps and --list
to control the tree formatting.
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.
Use lsblk --list-columns to get a list of all available columns.
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.
-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.
-H, --list-columns
List the available columns, use with --json or --raw to get
output in machine-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.
-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. Note that children[]
is used only if NAME column or --tree is used.
-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, --nvme
Output info about NVMe devices only.
-v, --virtio
Output info about virtio devices only.
-n, --noheadings
Do not print a header line.
-o, --output list
Specify which output columns to print. Use --list-columns 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.
-Q, --filter expr
Print only the devices that meet the conditions specified by
the expr. The filter is assessed prior to lsblk collecting
data for all output columns. Only the necessary data for the
lazy evaluation of the expression is retrieved from the
system. This approach can enhance performance when compared
to post-filtering, as commonly done by tools such as grep(1).
This feature is EXPERIMENTAL. See also scols-filter(5). For
example exclude sda and sdb, but print everything else ('!~'
is a negative regular expression matching operator):
lsblk --filter 'NAME !~ "sd[ab]"'
--highlight expr
Colorize lines matching the expression. This feature is
EXPERIMENTAL. See also scols-filter(5).
--ct name [: param [: function ]]
Define a custom counter. The counters are printed after the
standard output. The name is the custom name of the counter,
the optional param is the name of the column to be used for
the counter, and the optional function specifies the
aggregation function, supported functions are: count, min,
max, or sum. The default is count.
If the param is not specified, then the counter counts the
number of lines. This feature is EXPERIMENTAL. See also
--ct-filter.
For example, --ct MyCounter:SIZE:sum will count the summary
for SIZE from all lines; and to count the number of SATA
disks, it is possible to use:
lsblk --ct-filter 'TYPE=="disk" && TRAN=="sata"' --ct "Number of SATA devices"
--ct-filter expr
Define a restriction for the next counter. This feature is
EXPERIMENTAL. See also --ct and scols-filter(5). For example,
aggregate sizes by device type:
lsblk --ct-filter 'TYPE=="part"' --ct Partitions:SIZE:sum \
--ct-filter 'TYPE=="disk"' --ct WholeDisks:SIZE:sum
-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.
0
success
1
failure
32
none of specified devices found
64
some specified devices found, some not found
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.
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.
Milan Broz <[email protected]>, Karel Zak <[email protected]>
blkid(8), findmnt(8) ls(1), scols-filter(5)
For bug reports, use the issue tracker at
https://github.com/util-linux/util-linux/issues.
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/>. This page
is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
a bug report for this manual page, send it to
[email protected]. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-10.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page),
send a mail to [email protected]
util-linux 2.41.devel-537-e... 2024-01-28 LSBLK(8)
Pages that refer to this page: eject(1), mount(2), fstab(5), blkdeactivate(8), blkid(8), cfdisk(8), findfs(8), mount(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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