How to Quickly Find Disk UUIDs and Verify Filesystem Presence on Linux

Managing disks and filesystems is a core task for Linux system administrators. Knowing how to identify a device’s UUID and confirm that a partition is formatted helps avoid mounting errors and supports data recovery.

1. View Disk UUID

The UUID (Universally Unique Identifier) uniquely identifies storage devices, allowing the system to reference them reliably. Common ways to display UUIDs are:

Use blkid command: sudo blkid This prints all block devices with their UUIDs and associated filesystem types.

Use lsblk command: lsblk -o NAME,FSTYPE,UUID,MOUNTPOINT The output shows device name, filesystem type, UUID, and mount point.

Inspect /etc/fstab file: cat /etc/fstab This file lists devices that are automatically mounted at boot, often referencing their UUIDs.

2. Check Whether a Partition Contains a Filesystem

Before mounting or performing data recovery, verify that a partition is formatted. Useful commands include:

Use lsblk -f : lsblk -f /dev/sdc The command displays the filesystem type for each partition; an empty type indicates the partition is unformatted.

Use blkid again: sudo blkid If a partition lacks a filesystem, its entry may be missing or show no type.

Use file command: sudo file -s /dev/sdXN Replace /dev/sdXN with the actual partition device name. The output reports whether the partition contains recognizable filesystem data.

root@heaven:~# file -s /dev/sdc
/dev/sdc: Linux rev 1.0 ext4 filesystem data, UUID=7fa787b7-de75-40f7-b3ce-9944a2241cd8 (needs journal recovery) (extents) (64bit) (large files) (huge files)

By applying these commands, administrators can accurately manage disks, ensure correct mounting configurations, and maintain system reliability.