blkid

Updated

July 31, 2026

Overview

blkid probes devices for filesystem/RAID signatures and prints TYPE, UUID, LABEL. Use it when writing durable /etc/fstab entries.

Syntax

sudo blkid [options] [device...]

Common Options

Option Description
-p Low-level probe
-s TAG Only UUID, LABEL, TYPE, …
-o value\|export\|list\|udev Formats
-U UUID Path lookup by UUID
-L LABEL Path lookup by LABEL

Examples with Explanations

sudo blkid
sudo blkid /dev/sdb1
sudo blkid -o export /dev/sdb1
sudo blkid -s UUID -o value /dev/sdb1
sudo blkid -U 123e4567-e89b-12d3-a456-426614174000
sudo blkid -L data

fstab line sketch

UUID=$(sudo blkid -s UUID -o value /dev/sdb1)
echo "UUID=$UUID  /mnt/data  ext4  defaults  0  2"

Compare with lsblk

lsblk -f
sudo blkid

Notes

  • May need root to read some devices.
  • Cache file /etc/blkid.tab or similar is managed automatically.
  • Multipath/LVM paths may show multiple names for one UUID.