Mounting Failure Because of 32bit Limit

Recently I set up a Debian Squeeze on a 20TB RAID5 fileserver. When I tried to set up the xfs file system with partman, the following message appeared:

Der Versuch, ein Dateisystem vom Typ xfs auf /dev/sda als /srv einzubinden, ist fehlgeschlagen.

or in english:

The attempt to mount a file system with type xfs in /dev/sda at /srv failed.

I didn’t find the solution to this on google, I didn’t even find a similar problem. I could format the filesystem, but not mount it.
Later I thought about the underlaying hardware architecture, a 32bit dualcore server board. After having a look at the output of the df-command, it was clear. The volume had a sector count of 2147483647+ and was of type ee. What now? A complex decision: Split up the RAID, buy a 64bit board or use a file system like btrfs. I tried btrfs, but it’s performance was pretty bad because of my 2GB RAM. And because I’d like to run this server now, I abandoned to buy a new board and splitted up the RAID.