How to Upgrade Ubuntu 22.04 to 24.04 LTS: A Complete Guide

Link: https://www.cyberciti.biz/faq/how-to-upgrade-from-ubuntu-22-04-lts-to-ubuntu-24-04-lts/

Step 1 – Backup your system

Backing up your data before upgrading from Ubuntu 22.04 LTS to 24.04 LTS is vital for two reasons. First, even though thoroughly tested, unexpected issues can arise during the upgrade process. If something goes wrong, a backup ensures you can recover irreplaceable files like databases, code written in PHP/Perl/Python, documents, photos, or scripts. Second, upgrading to a new LTS version might introduce changes that cause some of your data incompatibility. A backup allows you to restore and migrate the data to a format compatible with the new Ubuntu version. Remember to back up your data before upgrading to Ubuntu. Don’t blame us if you lose everything!

How do I backup important data or everything?

Cloud providers usually offer backup options, such as taking a snapshot of your cloud server (here is guide for EC2 and Lightsail VM). Alternatively, you can use various backup tools like rsnapshot, tarsnap, restic, kbackup, duplicity, bacula, and Déjà Dup. Testing your backups and verifying that they can be restored is necessary, as is finding out how long it takes to restore the data.

Step 2 – Update your system

Run the apt command to upgrade all installed packages on the Ubuntu 22.04 LTS:
$ sudo apt update $ sudo apt list --upgradable | more $ sudo apt upgrade

Fig.01: Upgrading Ubuntu 22.04 LTS apps and packages to the latest version (click to enlarge)

Newer kernel available
The currently running kernel version is 5.15.0-1030-aws which is not the expected kernel version 6.5.0-1018-aws.  
Restarting the system to load the new kernel will not be handled automatically, so you should consider rebooting. 

Hence, reboot the Ubuntu Linux box using the reboot or shutdown:
$ sudo reboot

Fig.02: Rebooting the Ubuntu 22.04 LTS machine (click to enlarge)

Step 3 – Upgrading from 22.04 LTS or 24.04 LTS

You must install ubuntu-release-upgrader-core package:
$ sudo apt install ubuntu-release-upgrader-core
Ensure the Prompt line in /etc/update-manager/release-upgrades is set to ‘lts‘ using the “grep” or “cat”
$ grep 'lts' /etc/update-manager/release-upgrades $ cat /etc/update-manager/release-upgrades

Fig.03: Checking if the LTS prompt config is set or not on Ubuntu 22.04 LTS (click to enlarge)

Opening up TCP port 1022 using the ufw command or iptables command

For those using ssh-based sessions, open an additional SSH port using the ufw command, starting at port 1022. This is the default port set by the upgrade procedure as a fallback if the default SSH port dies during upgrades. The syntax for the ufw command to open SSH alternative TCP/1022 port with ufw is as follows:
$ sudo ufw allow 1022/tcp comment 'Open port ssh TCP/1022 as failsafe for upgrades' $ sudo ufw status
Here is an example for iptables:
$ sudo /sbin/iptables -I INPUT -p tcp --dport 1022 -j ACCEPT
Open the TCP/1022 port using your cloud server firewall if you have one. Here is how to do it with the AWS EC2 security groups or Lightsail instance:

Fig. 04: Open the TCP port 1022 using the CLOUD server firewall (click to enlarge)

Step 4 – Upgrading from Ubuntu 22.04 LTS to Ubuntu 24.04 LTS version

Finally, start the upgrade from Ubuntu 22.04 to 24.04 LTS version. Type:
$ sudo do-release-upgrade -d
Or you can try upgrading to the latest release using the upgrader from Ubuntu-proposed with version number. For example:
$ sudo do-release-upgrade -p '24.04.1 LTS'

Are you still getting the following error after August 29, 2024?

There is no development version of an LTS available.  
To upgrade to the latest non-LTS development release set Prompt=normal in 
/etc/update-manager/release-upgrades. 

There are multiple ways to upgrade Ubuntu 22.04 LTS before the release of 24.04.1 LTS, scheduled for August 29th, 2024. Here’s one safe method:

This note will automatically disappear after August 29th, 2024, as there will be no need for this kind of workaround. As a seasoned sysadmin and developer, I recommend waiting until the release of 24.04.1 LTS (scheduled for August 29th, 2024) before upgrading from Ubuntu 22.04 LTS. This ensures superb stability and minimizes potential compatibility issues with your apps. However, you can use these instructions for testing purposes. This is a great way to check if your applications will work seamlessly with Ubuntu 24.04 LTS.

Checking for a new Ubuntu release
 
= Welcome to Ubuntu 24.04 LTS 'Noble Numbat' =
 
The Ubuntu team is proud to announce Ubuntu 24.04 LTS 'Noble Numbat'.
 
To see what's new in this release, visit:
  https://wiki.ubuntu.com/NobleNumbat/ReleaseNotes
 
Ubuntu is a Linux distribution for your desktop or server, with a fast
and easy install, regular releases, a tight selection of excellent
applications installed by default, and almost any other software you
can imagine available through the network.
 
We hope you enjoy Ubuntu.
....
...
To sign up for future Ubuntu announcements, please subscribe to Ubuntu's
very low volume announcement list at:
 
  http://lists.ubuntu.com/mailman/listinfo/ubuntu-announce
 
 
Continue [yN]

Then it will tell you about ssh port what you already opened:

Reading cache
 
Checking package manager
 
Continue running under SSH? 
 
This session appears to be running under ssh. It is not recommended 
to perform a upgrade over ssh currently because in case of failure it 
is harder to recover. 
 
If you continue, an additional ssh daemon will be started at port 
'1022'. 
Do you want to continue? 
 
Continue [yN]

Finally, you need to confirm to start upgrade procedure:

Fig.05 : Upgrading Ubuntu from 23.04 or 22.04 to 24.04 (click to enlarge)

Dealing with “Remove obsolete packages?” message

You will get message as follows:

Remove obsolete packages? 
 
27 packages are going to be removed. 
 
 Continue [yN]  Details [d]

You need to review those carefully and only remove those packages if you do not need them. Otherwise, choose ‘N’ option.

System upgrade is complete

The movement has arrived. The system upgrade is complete. All you need to say ‘Y’ to reboot the system and pray that it comes online:

Fig.06: Rebooting into Ubuntu 24.04 LTS server (click to enlarge)

Step 5 – Verification

Use the command lsb_release command or cat command to check your Ubuntu Linux version. This command queries the /etc/os-release and provides you with the version information:
$ cat /etc/os-release
Here is what I see:

PRETTY_NAME="Ubuntu 24.04.1 LTS"
NAME="Ubuntu"
VERSION_ID="24.04"
VERSION="24.04.1 LTS (Noble Numbat)"
VERSION_CODENAME=noble
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=noble
LOGO=ubuntu-logo

And:
$ lsb_release -a
Outputs:

No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 24.04.1 LTS
Release:	24.04
Codename:	noble

Check the Linux kernel version as follows using the uname command:
$ uname -mrs Outputs: Linux 6.8.0-1014-aws x86_64

Please note that the Linux kernel version may very from time to time as new patches are applied to Ubuntu 24.04.xx LTS release.

Step 6 – Enabling 3rd party repos/mirros

After completing the upgrade to Ubuntu 22.04 LTS (or 23.10) to 24.04 LTS, ensure that you enable 3rd party mirrors and repositories; otherwise, you will not receive updates. Use the following cd command:
$ cd /etc/apt/sources.list.d $ ls -l
For example, my app repo was disabled during updates:
$ cat my-cool-apps.list
Outputs:

#deb [arch=amd64] https://dl.www.cyberciti.biz/linux/deb/ stable main

To enable it again, I commented out the line by removing the #:

deb [arch=amd64] https://dl.www.cyberciti.biz/linux/deb/ stable main

Then run the apt command:
$ sudo apt update $ sudo apt upgrade
Finally, clean up unwanted and unused leftover packages:
$ sudo apt autoremove --purge
Make sure to remove the iptables/ufw firewall rule that was added earlier to open the alternate SSH port at TCP/1022. For example:
$ sudo ufw show added # add the delete rule before the allow keyword $ sudo ufw delete allow 1022/tcp comment 'Open port ssh tcp port 1022 as failsafe option for upgrades'
See “How to delete a UFW firewall rule on Ubuntu / Debian Linux” for more info.

Wrapping up

Congratulations! You’ve successfully upgraded your Ubuntu system from 22.04 LTS or 23.10 to the latest 24.04 LTS using the command line. For in-depth details, explore the official Ubuntu 24.04 release notes and read manual pages using “man” or “help“:
$ man do-release-upgrade $ man apt $ man apt-get