[HPDD-discuss] Suggestions for greenfield Lustre 2.5 site: dumb or RAID HBAs?

Hello list, I have the opportunity for a greenfield Lustre 2.5+ site. We only have on-site experience with 2.1.x and hw RAID ldiskfs. A major decision point is OSS HBA dumb or RAID, and ldiskfs or ZFS; so could you chime in on, if you had the choice for 2.5+ would you go for: 1. RAID HBAs or dumb HBAs+RAID enclosure using hw RAID ldiskfs. Would you even consider hw RAID ZFS? E.g., some sample hardware (as we are mostly a Dell shop) Dell PERC+MD1200/C8000XD encl, Dell 6Gbps SAS (dumb) HBA + MD3200 encl 2. Dumb HBAs with ZFS raidz2 E.g. Dell 6Gbps SAS (dumb) HBA + MD1200 or C8000XD non-RAID enclosures Thanks for you wisdom. A. Alba