On Sunday 26 March 2006 1:13 pm, Per Jessen wrote:
Louis Richards wrote:
Perhaps two hardware RAID 5 arrays with hot spares and a software mirror of the two.
Yeah, that seems to be a good option. Unfortunately the Storageworks controller does not support mirrors built on top of RAID5 sets,
Drop the parity on the RAID5 and you have a RAID10. What's the point of wasting the time calculating parity? You lose space with RAID5 mirrored to another RAID5 versus same number of drives in a RAID10. Same number of points of failure also. RAID10 baby!
although it does support striping across multiple RAID5s.
RAID0 issues too. Any one RAID5 array goes down = no data. Are you thinking a RAID5 array is all on the same controller channel or are you thinking of spreading a RAID5 array across multiple channels on the same controller? Better performance spread across channels. Then if you RAID0 (via software RAID or via controller redundancy?) those RAID5 arrays is there a single point of failure?
Still, software mirroring of two hardware RAID5s sounds like a pretty good way to go.
Across controllers?
/Per Jessen, Zürich
Stan