Precautions for Package or Distro Upgrade

[solution.wand]

Hello Ubuntu Community,
I am new to Ubuntu and using Ubuntu Server ( Command Line ) for LAMP Development. I am using Ubuntu Server 12.04 LTS on VM at local network.
I am used to check updates and upgrades most of time. I have few question.

I am sure that linux is very flexible and reliable in upgrades but just for good practice:

1. Should we backup something before some "upgrade" is available in case of Package Upgrades or Distro Upgrades? Detailed guidance shall be quiet useful for a learner like me.

I am concerned because I don't want to lose my data or settings during any upgrade.

[ian-weisser]

Yes. If using a VM, and you have the disk space available, take a snapshot before upgrading.
You should backup regularly regardless of upgrades.

In my 9 years of Ubuntu, minor upgrades and release upgrades have led to no data loss at all.
Several hardware failures, thefts, admin mistakes, and other non-upgrade causes have led to merely minor data loss...because we had backups to restore from.