I just ordered five 1TB drives to install as a RAID 6 array in a Linux server (keeping the existing 1TB drive as a boot disk). I want to use Linux MD for RAID rather than a RAID card, to avoid lock-in. The intended use is for storing filesystems for Xen development environments and an AFP server for iPhoto/Aperture/Lightroom.
What things should I know before I set it up? For example, what would be a good choice of filesystem, and what chunk size should I use?