We're running a ZFS mirror at a customer site. At the next one, we're going with a beefier Sun Opteron server, and RAID-Z on a 3 disk pool, using 3 x 146GB 10K RPM SAS drives. The only shitty thing is that ZFS cannot boot yet, so we lose like 13GB per drive to a mirrored UFS partition to boot. Anyone playing with ZFS? Any of you data center guys?