How to upgrade a Debian 4 server?
 

Hey guys, I'm pretty new to Debian admin and I'm tasked with upgrading a Debian 4 to 6.

I know it's pretty easy to do, the thing is: what can I do to make sure everything works after the upgrade? How to avoid breaking the system would be the main concern.

Thank you.

It is tricky. There are a number of systems which have changes considerably between 4 and 6. Libc, grub and udev come to my mind. Right now 7 is stable but it seems you don't want to jump that far. In 7 Dovecot configuration might be incompatible.

In any way, I would step from 4 to 5 and then from 5 to 6.

Upgrading is straighforward, first upgrade the kernel, then the dist-upgrade.

You will face boot problems in one of these steps, which can be solved with the rescue disk.

jlinkels

I'd just install debian 7 rather than trying to upgrade.

BTW, though there isnt any offical announcement yet (as far as I know) on the end of life date for debian 6, if it follows the previous releases it will probably be end of life, out of support in may this year.