Successful booting with UUID

Guide to use UUID for consistent booting.

Guide to use UUID for consistent booting.

   Support Funtoo!

Get an awesome Funtoo container and support Funtoo! See Funtoo Containers for more information.

Introduction

When your system boots, the kernel looks at the fstab file to learn which partitions are available and where these should be mounted in the tree. Since the dawn of time, Unix time anyway, the convention was to list each partition from /dev. This works quite alright if you have only a single disk in your system, but modern computers, servers included, have an increasing amount of disks connected to their hardware and with that, the chance of 'getting it wrong' increases significantly. The result is a kernel panic! Fortunately, Linux has a solution: UUID or Unified Universal IDentification. It works this way: each time a partition is created, the partitioning tool also creates a random, large, unique number for it and assigns this to the partition. Due to its size, it's highly unlikely another partition in the machine will have the exact same number assigned to it. By using this UUID number in fstab the kernel can locate the correct partition to mount in the tree at the correct place and do so consistently. So, it's a good idea to use this UUID stuff, right? But how? Well, that's exactly the purpose of this guide.

Preparing your system

As is common in Linux, everything is a file (except for networking stuff, but that's beyond the scope of this guide) and so is the /etc/fstab file. To be safe, copy the contents of this file to a backup location.

cp /etc/fstab /etc/fstab.bak

Next, obtain the UUID's of each partition in your system. For that, we have the blkid command:

blkid /dev/sd* >> /etc/fstab

<more to come>

   Note

Browse all our available articles below. Use the search field to search for topics and keywords in real-time.

	Article	Subtitle
	Article	Subtitle
	Awk by Example, Part 1	An intro to the great language with the strange name
	Awk by Example, Part 2	Records, loops, and arrays
	Awk by Example, Part 3	String functions and ... checkbooks?
	Bash by Example, Part 1	Fundamental programming in the Bourne again shell (bash)
	Bash by Example, Part 2	More bash programming fundamentals
	Bash by Example, Part 3	Exploring the ebuild system
	BTRFS Fun
	Funtoo Filesystem Guide, Part 1	Journaling and ReiserFS
	Funtoo Filesystem Guide, Part 2	Using ReiserFS and Linux
	Funtoo Filesystem Guide, Part 3	Tmpfs and Bind Mounts
	Funtoo Filesystem Guide, Part 4	Introducing Ext3
	Funtoo Filesystem Guide, Part 5	Ext3 in Action
	GUID Booting Guide
	Learning Linux LVM, Part 1	Storage management magic with Logical Volume Management
	Learning Linux LVM, Part 2	The cvs.gentoo.org upgrade
	Libvirt
	Linux Fundamentals, Part 1
	Linux Fundamentals, Part 2
	Linux Fundamentals, Part 3
	Linux Fundamentals, Part 4
	LVM Fun
	Making the Distribution, Part 1
	Making the Distribution, Part 2
	Making the Distribution, Part 3
	Maximum Swappage	Getting the most out of swap
	On screen annotation	Write on top of apps on your screen
	OpenSSH Key Management, Part 1	Understanding RSA/DSA Authentication
	OpenSSH Key Management, Part 2	Introducing ssh-agent and keychain
	OpenSSH Key Management, Part 3	Agent Forwarding
	Partition Planning Tips	Keeping things organized on disk
	Partitioning in Action, Part 1	Moving /home
	Partitioning in Action, Part 2	Consolidating data
	POSIX Threads Explained, Part 1	A simple and nimble tool for memory sharing
	POSIX Threads Explained, Part 2
	POSIX Threads Explained, Part 3	Improve efficiency with condition variables
	Sed by Example, Part 1
	Sed by Example, Part 2
	Sed by Example, Part 3
	Successful booting with UUID	Guide to use UUID for consistent booting.
	The Gentoo.org Redesign, Part 1	A site reborn
	The Gentoo.org Redesign, Part 2	The Documentation System
	The Gentoo.org Redesign, Part 3	The New Main Pages
	The Gentoo.org Redesign, Part 4	The Final Touch of XML
	Traffic Control
	Windows 10 Virtualization with KVM