noble (8) lsblk.8.gz

Provided by: util-linux_2.39.3-9ubuntu6.2_amd64 bug

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.

       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 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 --help 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.

OPTIONS

       -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.

       -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.

       -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 --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>). See also option --shell.

       -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.

       -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.

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 <gmazyland@gmail.com>, Karel Zak <kzak@redhat.com>

SEE ALSO

       ls(1), blkid(8), findmnt(8)

REPORTING BUGS

       For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.

AVAILABILITY

       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/>.