Re: Oracle and RAID 5

We run Oracle V7 with RAID 5 on HP-UX and writes are noticably slow. A large cache will compensate for the inherent slowness of the technology, but not enough. Our RAID box is a "smart" RAID device. This means that if you have enough space for the device to play with it will reduce the RAID level which can result in better performance. I have not seen any numbers to prove this claim, but that's the line from our vendor. My feeling is that eventually all boxes will be "smart" and it's one more thing the DBA won't have to bother with.

The thing that the RAID 5 device does give you is reliablity. Providing the box is working correctly. That's the reason my manager opted for the RAID 5 solution.

We have all our database files on the RAID 5.

On Mon, 8 Nov 1999 15:17:28 -0500, "Jerry Gitomer" <jgitomer_at_hbsrx.com> wrote:

>No, it isn't dangerous ---- just terribly slow. If you want to
>make you AIX box run about as fast as a manual typewriter or an
>old fashioned adding machine just put the redo logs on your RAID
>5. In my last job the Unix Sysadmin configured one of our Oracle
>servers for RAID 5. Moving just the redo logs off of RAID 5
>resulted in a fivefold increase in performance. Yes, it was
>safe, but it wasn't fast enough to be usable.
>
>hth
>jerry gitomer
>
>Stephanie Wood wrote in message ...
>>I have a question for those people out there running oracle (v7)
>on Unix
>>(preferably AIX but any Unix OS will do). Are you running RAID
>5? Do you put
>>all of the Oracle files on the RAID 5 disks? According to a
>white paper from
>>Oracle it looks dangerous to put the redo logs, rollback
>segments and
>>temporary tablespace datafiles on RAID 5 disks (any files that
>do sequential
>>reads)....
>>
>>If you are running RAID 5 and have put all of the files for
>Oracle on the
>>RAID 5disks, have you had a disk failure and have you
>successfully recovered
>>from it?
>>
>>Stephanie
>>
>>
>
>
Received on Wed Nov 17 1999 - 22:06:52 CST