Re: RAID 5 on Oracle....?

From: Hari Om <hari_om_at_hotmail.com>
Date: 17 Sep 2003 14:22:21 -0700
Message-ID: <d1d5ebe4.0309171322.5fe40628@posting.google.com>

Thanks Thomas for your reply...and the linnk you forwarded.

What about this approach. I have two 18GB hdisk (mirrored with OS installed on it) and SIX 36GB hdisk.

It seems that since SYSTEM and REDO Log files are "NOT GOOD" for RAID 5, I came up with following. Instead of RAIDing (level 5) on 6 hdisk I would RAID only 3 disk and use them soley for DATA files.

So here is my layout:

hdisk0 --> AIX OS + Control File1 + Redo Log (Group 1)
hdisk1 --> AIX OS + Control File2 + Redo Log (Group 2)
hdisk2 --> Oracle SW + SYSTEM Tablespace files
hdisk3 --> REDO LOGS (Group 3)
hdisk4 --> ARCHieve Log Destination + UNDO

RAID 5 Disk (hdisk5 + hdisk6 + hdisk7) ---> DATA Files + TEMP

I cannot put my "hdisk3" under RAID 5 becos to OS RAID 5 is just one LOGICAL DISK and so I cannot multiplex them on different disk.

Will there be any issues in above setup....? Does someone here nay better idea then this one....?

THANKS! "Thomas T" <T_at_T> wrote in message news:<3f68766b$1_at_rutgers.edu>...
> "Hari Om" <hari_om_at_hotmail.com> wrote in message
> news:d1d5ebe4.0309170613.2723083f_at_posting.google.com...
> > I am using Oracle 9.2.0.1 on IBM AIX 5.1L System.
> >
> > Our box has 8 hard disk hdisk0-hdisk7 with hdisk0 and hdisk1 mirrored
> > and having SYSTEM BOS (Base Operating System).
> >
> > We are implementing RADID 5 on the remaining hard disk hdisk2-hdisk7
> > (each being 36 GB). Now if I implement RAID 5 on these disk.....to
> > system it would just be ONE SINGLE LOGICAL DISK. If that is the case
> > then how can I seperate different Tablespaces on different disk....
> > e.g.SYSTEM Tablespace should "not" be in same disk
> > e.g:Redo Log files "should" have a copy on different disk.....
> >
> > Now if OS treats the RAID as a "SINGLE BIG LOGICAL DISK" then how can
> > I seperate the above.....?
> >
> > What if I implement three RAID 5 (each of 2 disk)....just a
> > thought....
> >
> > My other school of thought says to use above RAID 5 of 6 hdisk and put
> > Redo log files on hdisk0-hdisk1 (becos these are "not" in my
> > RAID)....but would there be any issues on this.
> >
> > Any related informatino on this is appreciated....
> >
> > HARI OM
>
> Hari, I have a similar circumstance (same number of hard drives) on a Win2k
> system with 8i. 6 of the drives (2 thru 7) are raid5, giving us a ton of
> space. I had planned to re-do the storage unit into two raid 5 systems with
> 3 disks each. (Actually, I don't think you can -do- RAID5 with less then
> three disks.) Then I was going to chop up one huge tablespace that
> had -everything- into separate tablespaces, and separate things out among
> the logical drives. Then I was told about Oracle Myths, and pointed to
> here:
> http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:5071430793941
>
> Now I'm not going to bother doing anything with the storage unit, except
> keep up-to-date backups. It certainly makes my life easier! Hope that
> helps.
>
> -Thomas
Received on Wed Sep 17 2003 - 16:22:21 CDT