On Sun, 26 Mar 2006, L. Mark Stone wrote:
Quoting Per Jessen
: S Glasoe wrote:
Yeah, that seems to be a good option. Unfortunately the Storageworks controller does not support mirrors built on top of RAID5 sets,
There are two controller with each six SCSI channels, but only one controller will be visible at any one time.
Still, software mirroring of two hardware RAID5s sounds like a pretty good way to go.
Across controllers?
No, it would be on the same controller.
FWIW, we have seen 5-disk RAID5 arrays run with two failed disks. So, if you want maximum redundancy and have only one controller (with two channels), I'd set up one five-disk RAID5 array on each channel, with two hot spares (or one hot spare for each hardware RAID5 array if the controller does not support "floating" hot spares.) Then you can use software RAID1 with the RAID5 logical disks. Unless you are going to buy an IBM Shark or some other hardware storage device that has nested RAID arrays, that's about as good as you are going to get, IMHO.
5-disk raid5 arrays with 2 failed disks. I don't believe you.
Either you weren't using 5 "active" disks or it wasn't raid5. Somebody
show me how you can have a 5-disk raid5 with 2 failed disks (and remain
operational).
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