I am backing up a server installation of Debian 6.0.6 "Squeeze".
My question is, what is a good starting list of places that do NOT need to be backed up. Some examples of things that, to my knowledge would not be necessary:
I would in theory like to be able to perform a full restore of the system if, for example, both of the RAID drives crapped out.
Thanks!
Depending on whether you have them or not, /proc and /run should probably be ignored and /boot may not be mounted.
You will also find that /var/log/ contains a lot of data that you probably don't want to back up, but depending on compliance you may have to.
Files in /mnt may be NFS mounts from other servers or external media. NFS mounts would normally be backed up from the server where the disks are local but this isn't always the case. External media may or may not need to be backed up.
Mounted drives can be mounted in other places. Looking in /proc/mounts should tell you where this is the case.
Of course, your server(s) may be unique, and most of this could potentially be completely wrong.
The standard set of directories that I exclude in Linux backup processes are:
/dev
/lost+found
/media
/misc
/mnt
/net
/proc
/sys
and maybe /var/run, depending on what services you have running.
Also exclude any removable or remote filesystem mountpoints.
/and don't cross filesystem boundaries perhaps? If you have additional filesystems, then explicitly add them? This will ignore the ramdisk filesystem, and things like /proc,/sys, and /dev.