Do I have to reinstall Ubuntu if I upgrade to a newer version of it?

[likewise2]

Say I have to upgrade my Ubuntu from 17 to 18. Then, should I have to reinstall Ubuntu or I can put some command and it will be upgraded automatically. Sorry if its a too basic question to ask. I am a newbie to Linux.

[cruzer001]

With a current release a upgrade can be done with a few clicks.
The 17 series (17.04 & 17.10) have reached end of life and harder to upgrade.

https://help.ubuntu.com/community/EOLUpgrades

[deadflowr]

In a normal situation (where the system is still supported and the new release is also still supported) you have two options:

The graphical desktop way

The command line way


Note that both Ubuntu 17? releases are now dead so it's usually best to avoid upgrades from those.
It is possible to do such an upgrade see EOLUpgrades
But it's really far better in those situations to just do a clean install.

In all cases backups should be considered mandatory.

[monkeybrain20122]

Even in cases where you can "upgrade" I still recommend backing up your data and do a clean install, a lot faster and problem free.

[jdeca57]

in my experience there are two conditions in order to upgrade with minimal risks; the first is to keep your data safe and if you use cloud storage that is a big plus. Less safe is a separate /home partition but that is also a good solution. And secondly follow each upgrade, that means do not try to keep old versions but go from say 18.10 to 19.04. Coming from a 17.x is problematic. But an upgrade from 18.10 to 19.04? That works perfectly, probably because it is exhaustively tested.

[likewise2]

Should I make a full backup of the system before upgrade?

[Rubi1200]

Always best to do full backups before any major change to a system.

There is a list here of methods and tools for backups.
https://help.ubuntu.com/community/BackupYourSystem

[rbmorse]

Always best to do full backups even if you don't plan on changing the system..<g>, but yes, especially before a system change.

Having a full backup on hand is the best insurance against actually having to use it.

[oldrocker99]

Many people over the years have had less than satisfactory results upgrading in place. ALWAYS back your data first, and create a separate /home partition, and a 64GB system folder using gparted, the install disk setup. Then, copy your backup to that partition, and new installs, if you mount that partition as /home, will require only an installation to the / partition, and that makes installations easy!

Here are instructions for making the partitions during an installation: https://www.psychocats.net/ubuntu/installseparatehome.

Good luck!