PROMISE Pegasus R6 18TB (6 by 3TB) RAID System
Product No Longer Available
RAID 5 MTBF issue: will this take 4TB HDDs?
Several articles explain an issue with the MTBF (mean time between failures) being far too high (around 1 in 200, I believe), when drives in RAID-5 enclosures/multi-enclosure set-ups, where the drive pool is greater than 20TB's.
(Additionally, these articles mention the main business storage vendors also have clauses strongly dissuading admins set-up storage as RAID-5 accordingly for 20+TB storage pools.)
a) Given all this, is this enclosure going to be safe to use with 4TB drives (ie. 24TB, in a RAID-5 set-up)?
b) Or should it be a minimum RAID-6 when looking at using 4TB drives in this enclosure?
c) Or perhaps can RAID-5 safely be used, provided one has a completely separate enclosure for backup's (eg. using Time Machine, or something else to do them)?
Confusing to say the least. :-|
- Asked by James S
- Mar 21, 2013
1 Answer from the Community
Actually, 4T drives will only be agreed from Promise in a few weeks from now. I have 2 units with 6x 4TB drives = total of 24TB in RAID5 means 20TB available.
BUT these 2 units had several breakout and hangs......
You should wait to buy agreed 4TB drives !!!
- Answered by Patrick L
- Jun 15, 2013