Linux lsblk

lsblk is a command in Linux used to list information about block devices (such as hard drives, partitions, and optical drives). It displays device details and their dependencies in a tree structure by default, making it convenient for viewing the system’s storage layout.

Default Output Columns

The default output of lsblk typically includes the following key columns:

• NAME: Device name (e.g., sda, sda1).
• MAJ:MIN: Major and minor device numbers.
• RM: Whether the device is removable (1 for yes, 0 for no).
• SIZE: Device capacity.
• RO: Whether the device is read-only (1 for yes, 0 for no).
• TYPE: Device type (e.g., disk for disk, part for partition).
• MOUNTPOINT: The mount point of the device.

Common Options

• -f or --fs: Displays file system information, including file system type, UUID, and mount point.
• -l or --list: Outputs in list format rather than tree structure, facilitating script processing.
• -o or --output: Customizes the columns to display, for example lsblk -o NAME,SIZE,UUID.
• -p or --paths: Displays the complete device path (e.g., /dev/sda).
• -J or --json: Outputs in JSON format for programmatic parsing.

Important Notes

If you need to parse the output in scripts, it is recommended to explicitly specify the required columns using the -o option, as the default output columns may change across different versions.