I'm creating a shared storage server for ESX servers. The storage server is 2U Supermicro 24-bay rackmount server with 12x32GB Intel X25-e SSDs and 12x600GB Toshiba 10k SAS drives. Both SSDs and SAS drives are configured as RAID10 arrays which appear to the OS (Ubuntu 10.04.2 LTS) as big virtual drives. The RAID controller has a battery backup unit.
The SSD array would be "fast" datastore and the SAS array would be "big" datastore. I'm not yet decided whether I will use NFS or ISCSI. I will try both and decide based on my assessment of the performance and ease of handling differences ratio.
The question is: which filesystem to use for "fast" and which for "big" and which mount options?