Re: Oracle & RAID strategy question

Kate Kwiatek wrote:
>
> Greetings....
>
> I have a Sun E450 to configure for some small Oracle databases that will
> reside on the system. The system has 8 36-Gig hard drives and 2
> controllers. For now, the Oracle databases are fairly small and not real
> write-intensive at all. One of the databases is the database for our
> Oracle Portal application and the other database will hold financial
> information for a third-party forecasting and reporting tool called
> Control8 (KCI Computing). I'm not the actual unix sys admin who will be
> configuring the box, but the Oracle DBA driving the general
> configuration request.
>
> My dilemma is that I'm torn between which implementation of software
> RAID i should have the sys admins build. We must have complete
> redundancy so 4 disks will definitely be mirrored -- an unfortunate
> overhead, but my company can afford it. The two choices I have are the
> following:
>
> 4 disks each individually mirrored and manually laying out my Oracle
> directories to separate data, indexes and database software...
>
> or
>
> 2 logical volumes(4 disks-1controller each) striped and mirrored with an
> LVM like Veritas Volume Manager
>
> The problem I have with the second option is that I cannot directly
> control the separation of data and indexes in the Oracle environment,
> but since the databases are small and not highly-transactional, I am
> thinking the disk i/o benefit from the striping alone will negate this
> issue.
>
> Does anyone have any advice on which setup I should go with?? I
> understand the implications of failures for each, so I'm really just
> wondering which would offer better read-write performance for my
> particular database environment.
>
> I appreciate all advice....much thanks to all who reply:)
>
> Sincerely,
>
> Kate Kwiatek
> Manager - Technical Control
> Raytheon Company
> kwiatek_at_raytheon.com

Be nice if you could trade-in the 8x36 for 16x18... Oh well.

What you could do is imagine that you have an abundance of (mirrored) 4-disk groups. Then you layout 'data' on 1 of them, temporary stuff on another, archives on another etc. Now obviously initially these groups will all be sharing the same physical disks, but as your database grows you'll be in a good position to shift volumes to new disks (assuming you purchase them in batches of 4 disks)...

The only thing to really watch out for is if you get a hot spot on a single disk

hth
connor

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk (mirrored at
http://www.oradba.freeserve.co.uk)

"Some days you're the pigeon, some days you're the statue"