We've bought some Xserve and Xraid hardware for our new production and playout system. The Xraid came pre-configured with 2 Raid 5 partitions approximately 2.7 TB in size using 500 GB drives. Anyways, I'm now setting up Xsan to run on these machines so we can add more Xraids in the future. The question is how should I configure it?

The San needs to store its journalling and metadata, it needs to store it in the San itself. The manual says that it can be stored along with the user data, but it then says that volumes containing meta-data cannot be grown later on. I could set up a separate Lun for this but the minimum size would be 500GB without Raid or a whole TB with. A complete waste when the manual says it only needs 10-20GB. Also when I choose to upgrade, I'll lose any extra storage in the new Xraid as all the Luns have to be the same size.

What's the best way to do this, the administrators guide isn't particularly helpful.