If you can see this post, the new server is now running properly! :)

The new server is running Lenny, and is actually running on identical hardware (but with more RAM). The move to Lenny was a clean install, and resulted in some minor pain:

While migrating user mail there were some changes in UID/GID – easily fixed with ‘chown’ – although I initially didn’t change the group ownership, meaning that the IMAP server wasn’t happy. A quick ‘chgrp’ fixed that one, but I really should have used ‘chown user.group’

The previous server ran djbdns, mainly for the claimed ease of updating compared to BIND v8 (which I have used in a “production” system), so my first instinct was to do the same. This was not a good move – the official Lenny package meant that I couldn’t just transfer the files, and my attempt at migration was not successful. Quickest fix was to go to BIND v9 – which I actually prefer in some ways (the assumption that djbdns was easier to admin was wrong TBH).