[CentOS] strange partitioning problem

Wed Apr 25 02:17:36 UTC 2012
John R Pierce <pierce at hogranch.com>

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