Re: 2 questions re RAID

Thanks much for the specific info on Areca RAID cards. Very helpful.

On Jun 17, 2011, at 11:20 AM, Scott Marlowe wrote:

> The problem with RAID-5 is crappy write performance.  Being big or
> small won't change that.  Plus if the db is small why use RAID-5?

It's small enough that there's some other things going on at the same small server with 4 disk bays ;-) My thinking was
thatwrite-back cache might mitigate the poor write performance enough to not be noticed. This db doesn't generally get
bigbatch updates anyway, it's mostly a constant stream of small updates coming in and I have a hard time imagining
256MBof cache filling up very often. (I have at least a fuzzy understanding of how WAL segments affect the write load.) 

RAID-1 & RAID-10 are not ruled out, I'm just exploring options. And I'm not actually wanting to use RAID 5; it's RAID 6
thatI'm considering... 

--
Scott Ribe
scott_ribe@elevated-dev.com
http://www.elevated-dev.com/
(303) 722-0567 voice