RE: new asm disks

From: Lawie, Duncan <duncan.lawie_at_credit-suisse.com>
Date: Mon, 23 Oct 2006 09:26:56 -0400
Message-ID: <07150B51CE30744CBBB58E696139708DFDDF4B@elon11p32002.csfp.co.uk>

Randy,

Mixing different sized disks is not great practice if that is how you want to run. Ideally they will end up the same percent full ...

1* select name, total_mb, free_mb, 100*free_mb/total_mb pct_free

from v$asm_disk where group_number = 3 SQL> /

NAME                    TOTAL_MB    FREE_MB   PCT_FREE
--------------------- ---------- ---------- ----------
DATA1                      34851      25166 72.2102666
DATA2                      69711      50361 72.2425442

but you can get problems where they don't balance evenly.

However, if your intent is a straight swap, I would feel reasonably confident in adding the new disks, allow the rebalance to get going, then dropping the old disks.

(Mostly because it allows you to avoid the whole pain associated with your second question.)

HTH,
Duncan.

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Steiner, Randy Sent: 23 October 2006 14:05
To: oracle-l_at_freelists.org
Subject: new asm disks

My asm disk group is composed of 72 gig 15k rpm disks. I have new 320 gig 15k rpm disks that I want to add to the database, eventually replacing the existing disk. While the disks spec to be the same speed, they were made about 2 years apart, so I'm guessing there is still a difference in performance.

Question 1, is it still ok to add the new disk to the existing diskgroup and rebalance the old disk out?

Question 2 would it be better to create a new disk group and then figure out a way to move the tablespaces to the new diskgroup?

Thanks

Randy

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Received on Mon Oct 23 2006 - 08:26:56 CDT