How to Upgrade Ubuntu 21.10 from Ubuntu 21.04

First, check the current version of your machine.

[email protected]:~# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=21.04
DISTRIB_CODENAME=hirsute
DISTRIB_DESCRIPTION="Ubuntu 21.04"
[email protected]:~#

Then, Check that your system is up to date by running the following commands.

apt update && sudo apt upgrade -y 

NOTE: While running the command it'll prompt for several permissions give the permissions as required and Enter.

Output:

Restarting services...
 systemctl restart multipathd.service packagekit.service udisks2.service
Service restarts being deferred:
 /etc/needrestart/restart.d/dbus.service
 systemctl restart systemd-logind.service
 systemctl restart unattended-upgrades.service

No containers need to be restarted.

User sessions running outdated binaries:
 root @ session #1: apt[14439], bash[10674], sshd[9001]
 root @ user manager service: systemd[10432]
[email protected]:~# 

And reboot the server,

reboot

Once all updates are installed and rebooting server, Then install the update-manager-core package if it is not already installed.

apt-get install update-manager-core

Output:

[email protected]:~# apt-get install update-manager-core
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
update-manager-core is already the newest version (1:21.04.10).
update-manager-core set to manually installed.
The following packages were automatically installed and are no longer required:
  eatmydata libeatmydata1 net-tools python3-certifi python3-importlib-metadata python3-jinja2
  python3-json-pointer python3-jsonpatch python3-jsonschema python3-markupsafe python3-more-itertools
  python3-pyrsistent python3-requests python3-urllib3 python3-zipp
Use 'apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
[email protected]:~#

Go to the last line of /etc/update-manager/release-upgrades configuration file is set to ‘lts' if you only want LTS upgrades or to 'normal' if you want non-LTS upgrades.

vi /etc/update-manager/release-upgrades

Output:

# 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=normal

Now launch the upgrade tool by running the following command.

do-release-upgrade

NOTE: While running the command it'll prompt for several permissions.

Press y to confirm the upgrade.

After a restart, login and check the current Ubuntu version on your server by running the following command.

cat /etc/lsb-release

Output:

[email protected]:~# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=21.10
DISTRIB_CODENAME=impish
DISTRIB_DESCRIPTION="Ubuntu 21.10"
[email protected]:~#