We had a client on clearos 5.2 (rhel5) using zarafa and we were able to successfully upgrade them to clearos 6.3 (rhel6) on Friday.

It was a bit of work though the server was very slow the origional one it was a VM running on virtualbox.

However the new server is a dedicated Xeon 8 core with 16GB of ram so it's a very powerful server and is a RAID 1 1TB SAS drives

When I origionally was testing the migration of mysql dump I was concerned that it was not going to work and we would have to do an imapsync like the first server migration. However I found out it did work and the problem was this:

* Ldap - Ldap ID's were different due to us not being able to import clearos 5 ldap users and having to start from scratch because of that users had other users mailboxes which is why some users had a 16GB mailbox when they origionally had a 800MB mailbox.

This simply meaned we had to unhook and rehook the mailboxes to different accounts which was relatively easy on zarafa-admin (however quite tedius). A rsync of the /var/lib/zarafa/ from one server to the next for the attachments and we were in business! I do think for migrating other clients from clearos 5 to clearos 6 we will be doing scripts to re-hook and un-hook users next time to make it much easier on ourselves (The power of bash scripts!)

We are even doing a mysql replication for disaster recovery which should be helpful if something happens (although highly doubtful that both HD's will fail but you can never be too sure) along with doing zarafa-backup for the daily mailboxes etc.

Even though it took a while all in all it was quite a successful run and went much better then I anticipated now with mysql tweaking (thanks zarafa wiki) webaccess and webapp run much faster then the previous server giving mysql & zarafa a dedicated 4GB while the rest can be given to samba etc for file sharing and openvpn.

I definately like what you guys do so keep it up!