Upgrade Ubuntu
From: https://www.linode.com/docs/guides/how-to-upgrade-to-ubuntu-22
-04/
Upgrade to Ubuntu 22.04 LTS
Updated Thursday, March 30, 2023, by Jeff Novotny
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Although Ubuntu 20.04 LTS (Long Term Support) is still supported, users
should upgrade Ubuntu to the more recent 22.04 LTS. Upgrading to the new
release ensures the system can access the most recent security upgrades and
application packages. This guide describes how to perform an inline upgrade
from Ubuntu 20.xx or 21.xx to 22.04.
New Features in Ubuntu 22.04
Ubuntu 22.04 LTS from Canonical is also referred to as “Jammy
Jellyfish”. Ubuntu generally supports their LTS releases for five years,
which means Ubuntu 22.04 is supported until April 2027. This is superior to
the Ubuntu 20.04 schedule, where support ends in April 2025. In addition,
most application developers test their programs more thoroughly against the
latest LTS release.
In addition to the longer support period, Ubuntu 22.04 includes these other
features and improvements:
- Enhanced performance and better power efficiency.
- A better display, featuring double the frame rate.
- New power management options.
- Updated security patches.
- GNOME 42, which includes a streamlined user interface, on-screen
notifications, and better multi-monitor support.
- Increased customization options.
- Firefox availability through a Snap package.
- New releases of applications and toolchains. Updates and enhancements are
available for Apache, MySQL, Perl, PHP, PostgreSQL, Python, and Ruby.
- A new version (5.15) of the Linux Kernel.
Inline Upgrade versus Clean Install
There are two ways to upgrade a node. These are the inline upgrade method
and the clean install approach. This guide only explains how to perform an
inline upgrade. However, it is important to understand both methods to make
an informed choice.
The Inline Upgrade Method
In an inline upgrade, the primary node is upgraded in place using either
the
GUI or command line directives. Ubuntu downloads and installs the new
release of the operating system on the same system. The files and
applications on the system are left unchanged and the node can immediately
resume operations after the upgrade. Some of the advantages and
disadvantages of this method, and other factors to consider, are as
follows:
- This is the easiest and fastest method of upgrading a node. Depending on
the size of the new release, the node might be fully operational in as
little as 15 minutes.
- The Ubuntu upgrade procedure is well tested and generally reliable.
- Users do not have to remember to reinstall a critical program or import
data from the original node.
- It is impossible to avoid some downtime while the updates are installed
and the system reboots and initializes. During this period, any websites or
applications hosted on the node are inaccessible. It is crucial to declare
a
maintenance window or switch to a backup system for the duration of the
upgrade.
- There is a greater chance of complications. Some applications might not
work properly after the upgrade and might have to be reinstalled. There is
also a greater chance of data corruption.
- This method of upgrading tends to retain “digital residue”. This
includes unnecessary or outdated packages, patches, and data.
- This method is recommended if the system is only one release behind and
is
mainly running a widely used and tested configuration such as a LAMP stack.
An inline upgrade might run into more problems when the system
configuration
is complicated or includes in-house applications.
Warning
Although this process upgrades the Ubuntu operating system and most common
programs, it does not necessarily upgrade every application. It is
difficult
to predict how the upgrade might affect these programs.
The Clean Install Method
The clean install method takes the opposite approach to the inline upgrade.
This approach deploys a brand new Linode running the Ubuntu 22.04 release.
All necessary applications are reinstalled and the backed-up data from the
old node is copied over. After the new node is fully configured and
operational, the old node is decommissioned.
The pros and cons of a clean install are as follows:
- It is easier to troubleshoot any problems because there are fewer
dependencies.
- The configuration tends to be cleaner. Old packages and unwanted files
are
not copied over.
- This method takes a lot more effort and is more error prone. It is easy
to
forget to port over important applications and application data.
- This method is a better choice if the system is running a much older
release of Ubuntu or if the configuration is very convoluted. It is also a
good choice for systems under the control of an Infrastructure as Code
(IaC)
application, like Terraform or Chef. These applications allow
administrators
to automatically provision a new remote node with a standard configuration.
For an in-depth explanation of the clean install method, see the Linode
guide to manually upgrading a node.
Before You Begin
- If you have not already done so, create a Linode account and Compute
Instance. See our Getting Started with Linode and Creating a Compute
Instance guides.
- Follow our Setting Up and Securing a Compute Instance guide to update your
system. You may also wish to set the timezone, configure your hostname,
create a limited user account, and harden SSH access.
- Ensure there is at least 20 GB of disk space available. Verify the amount
of disk space availability using the df -Th command.
Note
This guide is written for a non-root user. Commands that require elevated
privileges are prefixed with sudo. If you are not familiar with the sudo
command, see the Users and Groups guide.
How to Upgrade to Ubuntu 22.04 LTS
This guide is designed for users who want to upgrade from Ubuntu 20.04 LTS
to Ubuntu 22.04 LTS. However, it is generally applicable for upgrades to
Ubuntu 22.04 from any release of Ubuntu 20.xx or 21.xx.
If the Linode is running Ubuntu 18.xx or any earlier release, first upgrade
it to Ubuntu 20.04 LTS. Then perform the steps in this guide to upgrade
from
Ubuntu 20.04 LTS to the 22.04 LTS. See the Linode guide to Upgrade to
Ubuntu
20.04 for more information. Alternatively, if the Ubuntu software and
applications are very old, it might make more sense to perform a clean
install instead.
Important
This operation cannot be canceled after it is started. Ensure there is a
stable connection to the Linode and backup power is available.
How to Prepare the Linode for the Upgrade
To increase the chance of a successful upgrade, ensure the operating system
and all applications are up to date. All data should be backed up and
active
user applications shut down.
To prepare the Ubuntu system for the upgrade, follow these steps.
- Upgrade the Linode and ensure it is up to date.
sudo apt update -y && sudo apt upgrade -y && sudo apt dist-upgrade -y
- To simplify the upgrade, remove unused packages and files.
sudo apt autoremove -y && sudo apt autoclean -y
- Reboot the node to ensure any new kernel upgrades are installed. Linode
makes new kernels available through the Linode cloud manager. Any updates
are automatically applied to the node upon a reboot. For more information,
see the Linode guide to monitoring and maintaining a system.
sudo reboot
- Make a backup copy of the system configuration and all application data.
The easiest way to do this is to back up the entire system. Subscribing to
the Linode Backup Service allows you to take a manual snapshot before the
upgrade.
- Stop as many non-critical user applications services as possible,
including
web and database servers. Focus on applications that might be subject to
data corruption. To see a list of the active services, use the command
systemctl | grep running.
sudo systemctl | grep running
...
apache2.service loaded active running The Apache HTTP Server
...
mysql.service loaded active running MySQL Community Server
- Use the command sudo systemctl stop to stop a service. The following
example demonstrates how to stop the Apache web server instance.
Important
Do not stop any essential system services such as ssh or any systemd
entry.
sudo systemctl stop apache2
- Allow connections on TCP port 1022 through the ufw firewall. This permits
Ubuntu to use a fallback port if the main connection drops. After adding
the
rule, reload the firewall.
sudo ufw allow 1022/tcp
sudo ufw reload
Firewall reloaded
- Confirm connections on TCP port 1022 are now allowed.
sudo ufw status
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Apache Full ALLOW Anywhere
1022/tcp ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Apache Full (v6) ALLOW Anywhere (v6)
1022/tcp (v6) ALLOW Anywhere (v6)
How to Install Ubuntu Release 22.04
The node is now ready for the upgrade. Ensure the update manager is
installed, then initiate the upgrade. The upgrade might take some time,
depending on the configuration, and must not be interrupted. Ensure there
is
enough time to complete the entire upgrade before proceeding.
Note
The upgrade operation can be performed using either a LISH session or an
SSH
connection. A LISH session is safer, but if SSH is used, the upgrade
manager
opens a second port for redundancy. This guide uses SSH for the procedure
to
demonstrate the additional steps required.
- Ensure the update-manager-core package is installed. On many systems, this
package might already be available.
sudo apt install update-manager-core
- Confirm the release-upgrader is set to the correct release update mode.
The
file /etc/update-manager/release-upgrades must include the line
Prompt=lts.
sudo cat /etc/update-manager/release-upgrades
File: /etc/update-manager/release-upgrades
# Default behavior for the release upgrader.
[DEFAULT]
# Default prompting and upgrade behavior, valid options:
#
# never - Never check for, or allow upgrading to, a new release.
# normal - Check to see if a new release is available. If more than
one new
# release is found, the release upgrader will attempt to
upgrade to
# the supported release that immediately succeeds the
# currently-running release.
# lts - Check to see if a new LTS release is available. The
upgrader
# will attempt to upgrade to the first LTS release available
after
# the currently-running one. Note that if this option is
used
and
# the currently-running release is not itself an LTS release
the
# upgrader will assume prompt was meant to be normal.
Prompt=lts
- Run the do-release-upgrade command to start the upgrade.
Note
To force an upgrade from the latest supported release to a development
release, use the command do-release-upgrade -d. This guide focuses on
upgrading to the latest supported release and does not use this flag.
sudo do-release-upgrade
- If the operation is performed using a SSH connection, Ubuntu verifies the
SSH connection details and asks whether to continue. Answer y to continue.
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?
- Ubuntu asks the user to confirm the new SSH port is allowed through the
firewall. The port should already be open. Press the Enter key to continue.
Starting additional sshd
To make recovery in case of failure easier, an additional sshd will
be started on port '1022'. If anything goes wrong with the running
ssh you can still connect to the additional one.
If you run a firewall, you may need to temporarily open this port. As
this is potentially dangerous it's not done automatically. You can
open the port with e.g.:
'iptables -I INPUT -p tcp --dport 1022 -j ACCEPT'
To continue please press [ENTER]
- Ubuntu reads through the list of packages, builds the dependencies, and
searches for internal package mirrors. If no mirrors are available, it
prompts for approval to rewrite the sources.list file. Enter y to continue.
Fetched 336 kB in 0s (0 B/s)
Reading package lists... Done
...
No valid mirror found
While scanning your repository information no mirror entry for the
upgrade was found. This can happen if you run an internal mirror or
if the mirror information is out of date.
Do you want to rewrite your 'sources.list' file anyway? If you choose
'Yes' here it will update all 'focal' to 'jammy' entries.
If you select 'No' the upgrade will cancel.
Continue [yN]
- Ubuntu downloads the new packages and files. It determines which packages
are no longer supported and requests approval to proceed. It also
calculates
how long the upgrade might take. To continue with the upgrade, answer y.
Note
To see details about the packages to be removed, installed, and
upgraded, enter d. Enter q to exit the details screen. Then enter y to
continue with the upgrade.
Do you want to start the upgrade?
14 installed packages are no longer supported by Canonical. You can
still get support from the community.
5 packages are going to be removed. 91 new packages are going to be
installed. 571 packages are going to be upgraded.
You have to download a total of 552 M. This download will take about
2 minutes with you connection.
Installing the upgrade can take several hours. Once the download has
finished, the process cannot be canceled.
Continue [yN] Details [d]
- Ubuntu displays a pop-up asking whether to restart the services after the
upgrade. Select either the button to automatically restart them or to
restart them manually.
Ubuntu Services Pop-up
- Ubuntu continues downloading the new packages. This can take a
considerable
length of time, especially if many applications have been installed.
However, Ubuntu echoes the package names when it installs and processes
them, allowing users to monitor the progress. During the upgrade, Ubuntu
uses a pop-up to ask users how to handle the sshd_config file. Select the
keep the local version currently installed option, and then choose .
Ubuntu SSH Configuration Pop-up
- Ubuntu locates any obsolete packages and asks the user whether to remove
them. Enter y to delete the outdated packages.
Searching for obsolete software
Reading state information... Done
Remove obsolete packages?
41 packages are going to be removed.
Continue [yN] Details [d]
- Ubuntu removes the packages and finalizes the upgrade. This stage might
also take some length of time. Ubuntu informs the user that the upgrade is
complete and prompts them to reboot the system. Select y to reboot and
finalize the upgrade.
System upgrade is complete.
Restart required
To finish the upgrade, a restart is required.
If you select 'y' the system will be restarted.
Continue [yN]
How to Perform Post-Upgrade Clean-Up Activities
Ubuntu has now been upgraded to version 22.04 LTS. After the Linode
reboots,
it is ready to resume operations. However, it is important to validate the
upgrade. There are also still a few security concerns to fix and clean-up
activities to perform. Log in to the Linode and perform the following
steps.
- Use the lsb_release -a command to verify the correct release of Ubuntu is
now installed. The Release attribute should be 22.04.
lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04.1 LTS
Release: 22.04
Codename: jammy
- Optional: To validate the kernel version, use the uname command.
uname -mrs
Linux 5.15.0-53-generic x86_64
- To increase security, close port 1022 in the ufw firewall. Reload the
firewall.
sudo ufw delete allow 1022/tcp
sudo ufw reload
- Confirm the firewall rules are updated.
sudo ufw status
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Apache Full ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Apache Full (v6) ALLOW Anywhere (v6)
- Ubuntu disables any third-party repositories during the upgrade. To search
for disabled repositories, switch to the sources.list.d directory and list
the entries.
cd /etc/apt/sources.list.d
ls -l
- Edit each list using a text editor. Remove the # symbol at the start of
the
affected entries, and save the file. In the following example, remove the #
symbol in front of deb [arch=amd64].
nano archive-application.list
File: archive-application.list
[DEFAULT]
deb [arch=amd64] https://apt.releases.application-name.com jammy main
- Update any third-party repositories and remove unnecessary packages using
apt commands.
sudo apt update -y && sudo apt upgrade -y && sudo apt dist-upgrade -y &&
sudo apt autoremove -y && sudo apt autoclean -y
Conclusion
Users can access security updates and new features by upgrading to the new
Ubuntu 22.04 LTS release. The two methods of updating a Linode are the
inline update or the clean install. This guide explains how to perform an
Ubuntu inline upgrade, which is the quickest and easiest method.
To prepare to upgrade a Linode to Ubuntu 22.04 LTS, update and upgrade the
node, back up the data, and stop all services. Use the do-release-upgrade
command to initiate the upgrade and follow all Ubuntu prompts. After the
upgrade, tighten up security, enable third-party archives, and perform some
clean-up tasks. For more information about the Ubuntu 22.04 LTS release, see
the Ubuntu server documentation.
More Information
You may wish to consult the following resources for additional information
on this topic. While these are provided in the hope that they will be
useful, please note that we cannot vouch for the accuracy or timeliness of
externally hosted materials.
This page was originally published on Monday, November 7, 2022.