m.novelli wrote:NLSAS disks (similar to WD Red Pro)
RAID 5 + 1 hot spare
Just curious....why RAID 5??? Just about every opinion that I have read said to stay away from RAID 5 as the chances of a hard drive failure upon a rebuild of the array is pretty high. Therefore, you would lose everything that was on the array.
RAID6 write penalty is too high IMHO for a storage dedicated to backups
In 15+ years of IT I've never lost a RAID5... All my servers and storage always have firmware updated (both raid card and disk firmware). I use only Dell PowerEdge servers. In the last years I've prepared many Veeam Backup servers with 2 - 3 - 4 and now 6 TB NLSAS disks, so far so good. I always use an hot spare. On a recent Dell PowerEdge T630 where failed a 6TB disk, the automatic hot spare coverage took about 8 hours to complete the rebuild (it was a RAID5 made of nine 6 TB disks)
I can't see why a disk that get intensive writes during backups should have an higher failure rate due to intensives reads in case of array rebuild...