On Nov 8, 2007 1:22 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
> Mine too. I would suggest though, that by the time you get to 14
> disks, you switch from RAID-5 to RAID-6 so you have double redundancy.
> Performance of a degraded array is better in RAID6 than RAID5, and
> you can run your rebuilds much slower since you're still redundant.
>
couple of remarks here:
* personally im not a believer in raid 6, it seems to hurt random
write performance which is already a problem with raid 5...I prefer
the hot spare route, or raid 10.
* the perc 5 sas controller is rebranded lsi megaraid controller with
some custom firmware tweaks. for example, the perc 5/e is a rebranded
8408 megaraid iirc.
* perc 5 controllers are decent if unspectacular. good raid 5
performance, average raid 10.
* to the OP, the 15k solution (dell 2900) will likely perform the
best, if you don't mind the rack space.
* again the op, you can possibly consider combining the o/s and the
wal volumes (2xraid 1 + 6xraid 10) combining the o/s and wal volumes
can sometimes also be a win, but doesn't sound likely in your case.
merlin
merlin