I have an Ubuntu 6.10 server running ISPConfig 2.2.29. As 6.10 is no longer supported I want to upgrade/reinstall to 8.04.2 LTS so that the server does not require much attention until it's written off (security updates are done automatically). The upgrade path would be 6.10 to 7.04, 7.04 to 7.10 and then finally 7.10 to 8.042 LTS. This appears to be quite time consuming so I think that a new, clean install of the OS would be best (and fastest). My question now is: what files do I need to back up in order to restore the ISPConfig installation without too much downtime (and hassle) for the users? I know that a reinstall of ISPConfig followed by restoring a backup of the ISPConfig database in theory should cover "almost" everything, but when I look at my /etc/passwd file I see that the ISPConfig users are in that list as well. Do I only need to backup /etc/passwd, /etc/shadow and /etc/group or are there more files?