Provided by: util-linux_2.39.1-4ubuntu2_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/>.