lsblk

List all storage devices in a tree-like format

$ lsblk

$ lsblk [[-a|--all]]

$ lsblk [[-b|--bytes]]

$ lsblk [[-f|--fs]]

$ lsblk [[-i|--ascii]]

$ lsblk [[-t|--topology]]

$ lsblk [[-e|--exclude]] [1,7,...]

$ lsblk [[-o|--output]] [NAME,SERIAL,MODEL,TRAN,TYPE,SIZE,FSTYPE,MOUNTPOINT,...]

lsblk [options] [device...]

-a, --all
    List all block devices. The default is to exclude empty devices.

-b, --bytes
    Print SIZE in bytes rather than in human-readable format.

-d, --nodeps
    Don't print slaves or holders.

-D, --discard
    Print discard (trim) capabilities.

-e, --exclude list
    Exclude devices by major number (list is a comma-separated list).

-f, --fs
    Output filesystem information.

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

-I, --inode
    Print inode information.

-J, --json
    Use JSON output format.

-l, --list
    Use list format.

-m, --perms
    Output permissions information.

-n, --noheadings
    Don't print headings.

-o, --output list
    Output columns. See below for a list of available columns.

-O, --output-all
    Output all columns.

-P, --pairs
    Use key="value" output format.

-r, --raw
    Use raw output format.

-S, --scsi
    Output SCSI information.

-t, --topology
    Output topology information.

-v, --version
    Display version information and exit.

-w, --width width
    Specify output width.

-x, --sort column
    Sort output by column.

The `lsblk` command is a utility used to list information about block devices on a Linux system. It displays information about all available block devices (except RAM disks) and provides details about their partitions, sizes, mount points, and other related attributes. Unlike `fdisk`, `lsblk` does not provide partition management capabilities; it's purely an information tool. `lsblk` is part of the util-linux package, making it widely available across different Linux distributions. It reads the /sys filesystem to gather information about the connected storage devices, offering a more user-friendly output compared to directly reading the device files. `lsblk` is valuable for system administrators and users who need to quickly identify storage devices and their configurations, troubleshoot storage-related problems, or understand the overall storage layout of a system. It is particularly helpful in environments with complex storage configurations, such as those involving RAID arrays or logical volumes.

The information displayed by `lsblk` is read from the `/sys` filesystem. Therefore, the command requires appropriate permissions (usually root) to access all device information. It also may not represent the actual device configuration if devices have been changed without informing the system, and will fail if /sys is not mounted or accessible.

The `--output` option allows you to specify which columns to display. Some common columns include:
NAME: Device name
MAJ:MIN: Major:minor device number
RM: Removable device
SIZE: Size of the device
RO: Read-only
TYPE: Device type (disk, partition, etc.)
MOUNTPOINT: Mount point
FSTYPE: Filesystem type
LABEL: Filesystem label
UUID: Filesystem UUID

The `--json` option is useful for scripting and automation. It provides a structured output format that can be easily parsed by other tools.

The `lsblk` command was introduced as part of the util-linux package. It's been widely adopted across various Linux distributions due to its ease of use and comprehensive display of block device information. Its development aimed to provide a more user-friendly interface to underlying device information than directly parsing files in `/dev` or using `fdisk`.

fdisk(8), mount(8), blkid(8), parted(8)