Why is `lsblk -f` a great command? See all your Linux filesystem types fast!

The command lsblk -f (or lsblk --fs) is a powerful utility in Linux used to list block devices along with detailed information about their filesystems. It provides a tree-like view of block devices, making it easy to understand their relationships, and the -f option specifically enriches this output with filesystem-specific data.

Key Information Displayed by lsblk -f

When you execute lsblk -f, the output typically includes the following columns, offering comprehensive filesystem details for each block device or partition:

• NAME: The device name (e.g., sda, sda1, nvme0n1p1).
• FSTYPE: The type of filesystem detected on the device (e.g., ext4, xfs, ntfs, vfat, swap, lvm2_member). This column is central to the -f option.
• FSVER: The version of the filesystem (e.g., 1.0 for ext4). This might not be present for all filesystem types.
• LABEL: The filesystem label, if one has been set. This is a user-friendly name assigned to the filesystem.
• UUID: The Universally Unique Identifier for the filesystem. This is a persistent and unique identifier, often used in /etc/fstab for mounting.
• FSAVAIL: The available space on the filesystem. This is typically shown only for mounted filesystems.
• FSUSE%: The percentage of the filesystem space that is currently in use. This is also typically shown only for mounted filesystems.
• MOUNTPOINT (or MOUNTPOINTS): The directory in the filesystem hierarchy where the device is mounted. If the device is not mounted, this column will be empty. For devices with multiple bind mounts or in certain containerized environments, MOUNTPOINTS might show multiple paths.

Common Use Cases

lsblk -f is invaluable for various system administration and troubleshooting tasks:

• Identifying Filesystems: Quickly determine the filesystem type on hard drives, SSDs, partitions, LVM logical volumes, and removable media.
• Obtaining UUIDs and Labels: Easily find the UUID or LABEL for a partition, which is crucial for configuring persistent block device naming in /etc/fstab.
• Verifying Mount Status: Check which filesystems are mounted and where, along with their usage statistics.
• Troubleshooting: Helps in diagnosing issues related to unmountable filesystems, incorrect filesystem types, or missing labels/UUIDs.
• Disk Management Preparation: Before formatting or partitioning, it helps to understand the current state of filesystems on the devices.

By providing a clear, hierarchical, and filesystem-aware overview of block devices, lsblk -f significantly simplifies the inspection and management of storage in a Linux environment.