blkid

Overview

The blkid command locates and prints block device attributes. It’s used to find UUID, LABEL, TYPE, and other filesystem information.

Syntax

blkid [options] [device...]

Common Options

Option Description
-c file Read from cache file
-g Garbage collect
-h Display help
-l Lookup only
-L label Look up device by label
-U uuid Look up device by UUID
-p Low-level probe
-s tag Show specified tag
-t NAME=value Find by tag
-v Verbose output
-w file Write to cache file

Output Tags

Tag Description
UUID Filesystem UUID
LABEL Filesystem label
TYPE Filesystem type
PTTYPE Partition table type
PARTUUID Partition UUID
PARTLABEL Partition label
USAGE Usage type
VERSION Version info

Key Use Cases

  1. Device identification
  2. Filesystem detection
  3. UUID lookup
  4. Label lookup
  5. System configuration

Examples with Explanations

Example 1: Basic Usage

blkid

Show all block devices

Example 2: Specific Device

blkid /dev/sda1

Show device attributes

Example 3: Find by UUID

blkid -U "uuid-string"

Lookup device by UUID

Common Usage Patterns

  1. List all:

    blkid

  2. Find label:

    blkid -L "label"

  3. Show type:

    blkid -s TYPE

Security Considerations

  1. Root access
  2. Device permissions
  3. Cache security
  4. Information exposure
  5. System access

Additional Resources

Best Practices

  1. Use UUIDs
  2. Regular updates
  3. Cache management
  4. Documentation
  5. Verification

Filesystem Types

  1. ext4
  2. xfs
  3. btrfs
  4. swap
  5. vfat

Troubleshooting

  1. Device access
  2. Cache issues
  3. Missing info
  4. Version conflicts
  5. Format errors