[CentOS] RAIDs and JBOD?

John R Pierce pierce at hogranch.com
Wed Nov 11 00:30:44 UTC 2009

Robert Heller wrote:
> No.  You can use as many disks as you like for RAID 5.  The 'parity' is
> not actually 1 bit.  The capacity of a N disk RAID 5 (where N >= 3), is
> (N-1)*sizeof(one disk).

within reason.   Its usually not a good idea to make a single raid5 set 
much over 7-8 disks as the repair time becomes brutal, and the 
performance degradation after a single drive failure is extreme.   For 
very large numbers of drives, build multiple raid5 sets and stripe them 
(raid 0+5 sometimes called raid 50).

I will say again, I really prefer mirroring and raid 10/0+1 ... disks 
are cheap, data loss and/or downtime is expensive.

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