Re: Oracle & Raid

Just a rule of thumb. Application tablespaces that are mainly read only should be raid5. Those that are heavy update, or insert should be striped, and mirrored. The following oracle related files are as so: Index tablespaces follow the same rules.

System tablespace - Striped, with 2 mirrors. This is just too important to loose.
control files, redo logs - striped and mirrored (either OS or oracle mirroring), but DO MIRROR.
control files - I also suggest 2 mirrors for controlfiles. Rollback and Temp. At least striped, mirrored if you can't have the system down at all.

Try to use multiple controllers for each volume. Use raw devices if you are adventurous. The speed gains and the flexibility with volumes are well worth the pain.

Just guessing at your sizes:
figure the following numbers.

system - 100M*3 - 300M
redo - 50M*2*3 - 300M
control 10M*3 - 30M
Your Application Data 20GB - figure using 6+1 you should only use about 25GB of your 90
heavy write data .5GB - Striped and mirrored 1GB -- total so far. (under 30GB)

I can't really judge your usage of Rollback and temp, but Rollback in a mostly read only database should be small. Let's say 1GB (use 2) Temp will depend on your sorts. Let's say it is big (6GB * 2)

You have only used about 1/2 of your real 90GB up to this point.

Make sure you use different disks and controllers for the mirrors.

If you are running in archive log mode (highly suggested) make sure that the archive log dest is not raid5. Use a mirrored and striped file system. (it won't need to be real big, because you probably won't have a lot of redo activity).

10GB * 2 (20GB)

You are now left with 25GB of raw disk to use for expansion. Oracle if you haven't installed it would be very well suited to be raid5. Most likely under 1GB.

--
Bob Fazio
Remove no.spam from my email to reply

<yb98_at_inter.net.il> wrote in message news:37C81982.19B58DF0_at_inter.net.il...
> i have a problem in my organization.
> we have about 10 disks of 9GB for the oracle use.
>
> we do not know how to configer it under the raid.
> does some one know any publications about it?
> does some one have any idea?
>
> our db has a very big part of read only table (about 20GB)
> and a small part whitch beening update (0.5GB)
>
> thanks
>
Received on Mon Aug 30 1999 - 22:13:52 CDT