On 04/24/12 2:24 PM, Eero Volotinen wrote: > Anyway, with 18TB of raid 6 might cause performance problems .. raid > 60 or raid 10 looks much better solution. 18TB of raid6 is only 8 3TB drives (6 + 2 parity).... thats not an unreasonable size for a raid6 set. for the 81TB nearline storage boxes I built for a data archive application, I formatted each box (using a megaraid sas2 9260-8i card and 36 3TB SAS drives) as 3 x 11 x raid60, plus 3 hot spares, and then made one big XFS on that. Its working out quite nicely. I think 10 or 12 disks per raid5 or 6 is a good upper limit. rebuild time from a single failure was 12 hours, and from a double failure in the same raid plex, 18 hours. -- john r pierce N 37, W 122 santa cruz ca mid-left coast