Re: asm on san

From: Mladen Gogala <>
Date: Sun, 14 Dec 2008 19:16:09 +0000 (UTC)
Message-ID: <gi3m1p$l0m$>

On Sat, 13 Dec 2008 11:21:35 -0600, Michael Austin wrote:

> And when it comes to
> performance, as I stated, there are but a handful of systems that RAID10
> vs RAID5 would ever make any real difference in performance. If I
> needed to build one of those systems, you could bet it would be a
> completely dedicated environment.

I have had problems with "waiting for free buffers" when one of the data files was located on a RAID 5 LUN (EMC CX 700, rather high end SAN). When the file was copied to a RAID 1+0 LUN, the problems with DB writer went away. That was a fairly high end OLTP database. Unfortunately, not all SAN devices have that many gigabytes of memory. I still subscribe to the BAARF doctrine: RAID 5 is not for databases.

Received on Sun Dec 14 2008 - 13:16:09 CST

Original text of this message