Understanding PARTUUID vs. UUID in Linux: A Comprehensive Guide

Learn the differences between PARTUUID and UUID in Linux. Understand their use cases, and optimize your system. A comprehensive guide!

Introduction

When managing partitions in Linux, understanding unique identifiers is crucial. Whether you’re a system administrator, developer, or curious user, this guide will demystify two essential identifiers: PARTUUID and UUID. Let’s dive in!

1. UUID (Universally Unique Identifier)

What is UUID?

• UUIDs are 128-bit hexadecimal values assigned to filesystems within partitions.
• They ensure uniqueness across various layers (filesystems, partitions, RAID, LUKS, LVM).

Use Cases:

• Mounting Filesystems: UUIDs are used in /etc/fstab to mount filesystems during boot.
• Referencing Partitions: Scripts and configuration files often use UUIDs to identify specific partitions.

Advantages:

• Universally recognized and supported.
• Works even if the filesystem type is unknown.

2. PARTUUID (Partition Table UUID)

What is PARTUUID?

• PARTUUIDs are identifiers at the partition-table level.
• They are a standard feature for all partitions on GPT-partitioned disks.

Use Cases:

• Identifying Partitions: PARTUUIDs help uniquely identify partitions, especially in scenarios like encrypted volumes.
• Stability Across Filesystem Changes: Unlike UUIDs, PARTUUIDs remain constant even if you reformat or change the filesystem.

Differences from UUID:

• PARTUUIDs are tied to the partition table, not the filesystem.
• They are accessible without assumptions about partition contents.

3. Finding UUID and PARTUUID in Debian Linux

Using blkid:

Retrieve partition UUIDs with the following command:

• Run blkid in the terminal to see UUIDs of all partitions.
• List the contents of /dev/disk/by-uuid/ to find the symbolic links to actual devices.

Using udevadm:

Additional Resources

1. PARTUUID:
   • Find detailed information in the Debian Wiki.
   • Refer to the crypttab(5) man page for using PARTUUID with encrypted devices.
2. UUID:
   • Explore the uuid(3ossp) man page for comprehensive UUID details.
   • For general UUID usage, check out the uuid(1) man page.

I hope this Understanding PARTUUID vs. UUID helped you to understand the difference. If you like this post, please recommend it and link it to forums, etc.