Tracy R Reed wrote:
> 
> [NetAPP says] use only RAID1 or RAID6. This is in line with CMU's
> suggestion that the odds of a double failure in a RAID5 is greater than
> we think.

Odd. NetAPP uses RAID 4.

http://72.14.253.104/search?q=cache:Hn3aFdnbmSAJ:www.netapp.com/library/tr/3295.pdf

  The standard RAID group type on NetApp appliances has been RAID4, and
  this RAID group type continues as an option going forward. 

They have this new RAID-DP thing, which is not quite RAID-6:

   Whereas in RAID4, the parity disk stores row parity across the disks
   in a RAID4 group, the additional RAID-DP parity disk stores diagonal
   parity across the disks in a RAID-DP group. With these two parity
   stripes in RAID-DP, one horizontal and the other diagonal, data
   protection is obtained even in the event of two disk drives failing
   in the same RAID group. 

-john


-- 
[email protected]
http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list

Reply via email to