Re: A DBA philosopical question

From: Bob Jones <email_at_me.not>
Date: Fri, 02 Dec 2005 02:00:48 GMT
Message-ID: <kVNjf.25205$dO2.24471@newssvr29.news.prodigy.net>

<jared.hecker_at_gmail.com> wrote in message news:1133466649.707467.142860_at_g43g2000cwa.googlegroups.com...
>I am consulting at an all-Windows shop, running mostly 9.2.0.3 -
> 9.2.0.6 under Windows 2003 Server. The one no-no I've encountered so
> far is that their SAN array is all RAID 5. As they have grown by
> acquisition, this is an old, old StorageTek unit that supposedly does
> not support RAID 1,0.
>

What's wrong with using RAID 5?

> I am looking into I/O constraint issues :-). What I found is pretty
> surprising, and thus generates the "philosophical question". Their
> Oracle servers are configured with one internal drive and two logical
> volumes from the SAN array. The DBA's here rightly multiplexed their
> control files, one on each drive. Looking at the physical disk access
> screens via OEM, I see that the C: drive takes far longer to write. It
> contains control01.ctl. So the question is: Is it better to multiplex
> to two spindles (the faster SAN volumes) to gain the I/O, or is it
> better to multiplex to three drives?
>

There are usually little I/Os on control files. I doubt you are going to gain much performance by removing the copy on C:. It should be easy to test it out. Received on Thu Dec 01 2005 - 20:00:48 CST