lsblk

lsblk is a standard Linux command-line utility that lists information about block devices. It is part of the util-linux package. The program queries the kernel and sysfs to present a tree-like view of all block devices, including physical disks, partitions, and logical volumes, showing how they relate to each other. The default output includes columns such as NAME, MAJ:MIN, RM, SIZE, RO, TYPE, and MOUNTPOINT, and it can display devices in a hierarchy where partitions appear under their parent disk.

Common uses include quickly identifying the layout of storage devices, locating mount points, and verifying that partitions or logical volumes exist as expected. lsblk does not attempt to mount or modify devices; it is a read-only inventory tool.

Options enable more precise output. For example, -a shows all devices (including empty ones); -b prints sizes in bytes; -d limits output to top-level devices (no partitions); -f shows filesystem information such as FSTYPE, LABEL, UUID, and PARTUUID; -l produces a flat list; -n suppresses the header; -p prints full device paths (e.g., /dev/sda); -o allows custom column selection; -J outputs JSON, which is convenient for scripting. The command can be combined with other utilities to parse results.

Related tools include blkid, fdisk, parted, and df, which complement lsblk by providing additional details or different views of storage usage.