RAID Performance with Oracle

Seth Mos knuffie at xs4all.nl
Mon Mar 24 01:21:01 CST 2003


At 17:09 24-3-2003 +1100, Paul wrote:
>
>Hey All,
>
>I am helping someone out with quite an intensive database with a lot of
>writes (and reads).  They have Oracle 9i on SuSe SLE8 and using RAID 5 
>(PowerEdge2600 with Perc4di).
>It appears it is taking time to write to the disks.  In this case it is
>not feasable right away to switch it from RAID 5 to RAID 1+0 or 0+1 or
>similar.

Do not put a Large database on a raid5 software or hardware raid.

Raid 0,1 and 10 are safe for use with databases.

>Does the Perc4Di support RAID 1+0 arrays?

Yes.

>I appears that it may be taking up to 8 seconds to write to the Redo log
>files.
>
>Is there anything I can do to optimize the database for RAID 5 use?

No. Raid 5 requires 5 read write operations on the hardware level for one 
update which hurts really badly.
This is why it is inherently bad for something dynamic like a database.

Cheers

--
Seth
It might just be your lucky day, if you only knew.




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