Re: Optimal RAID configurations for relational databases

It all depends on the application. If it's write intensive, you'll pay a penalty with raid-5. Raid 0+1 (striped and mirrored) is what I prefer with Oracle. The only penalty with that is the additional disk cost, which is really cheap these days.

Oracle should usually be divided up somthing like this

2 drives for online logs	write exclusive. No raid needed
				(Oracle mirrors by logs in software)
				These drives can usually be pretty
				small. 1 or 2g should be more than
				enough
1 drive for archived logs	write exclusive. raid 0+1.
1 drive for rollback segments	write intensive. raid 0+1
1 drive for temp tablespace	read/write even mix. raid 0+1.
1 drive for indexes		read intensive. raid 5 usually ok
1 drive for tables		read intensive. raid 5 usually ok

For the indexes and tablespaces, raid 5 is ok in most OLTP environments. But if you've got a data warehouse or some other application that does bulk data loading, it'll really slow performance.

On Wed, 09 Dec 1998 16:04:48 GMT, kbuttler_at_mcs.net wrote:

>We are in the process of building several Compaq Proliant servers for both MS
>SQL 6.5 and Oracle 8.0 on NT. These servers both have a Compaq Smart 2DH
>Array Controller and five 4.3GB hard drives. We are in the middle of a
>heated debate with our DBA's on how these servers should be built (I'm on the
>NT side of things, so pardon my ignorance in relational databases)
>
>My question is this: Will we face a significant performance hit by using RAID
>5 across these five drives are is it better to use RAID 0 or RAID 1? Why?
>
>any input would be GREATLY appreciated!
>
>kevin.
>
>-----------== Posted via Deja News, The Discussion Network ==----------
>http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own

--
Chuck Hamilton
chuckh_at_safeaccess.net

"Therefore the Lord Himself will give you a sign:
Behold, a virgin will be with child, and bear a son,
and she will call His name Immanuel." (Isa 7:14 NASB)