[ Thanks to Marius
Ducea for this link. ]
“One of the greatest advantages of debian over other
linux distributions is that we can upgrade our systems live from
one version to another (hopefully with minimal damage or impact to
the running system), while other distros like rhel will not
recommend their users to ever do this but to do a full new
installation and migrate over their user data afterwards. Obviously
it is a great advantage to be able to perform a live upgrade from
one version to the other, and from my experience this has not
caused problems, but even so, if this is a production server or
just a system you care for and it is not for testing, I would start
by making a backup of the system and be prepared in case it will no
longer work after this. Just in case… Also you should start by
reading the release notes of the new version and look for any
incompatibilities (hardware or software) or changed things that
could affect your particular setup.”