Re: ASM rebalancing

From: Oscar Ofiana <oj.ofiana_at_gmail.com>
Date: Fri, 22 May 2015 14:55:42 +1000
Message-ID: <CAPjcp6C4OuJTrE9VK-s-ZtdL2Hu55202hHWgLfDJBDVe_pOs0A_at_mail.gmail.com>

I wondered about this as well, since I also vaguely recalled reading somewhere that ASM would do this. The closest I could find though is Intelligent Data Placement, where you can specify the hot data be placed on the outermost disk tracks. Hardly an automatic process though.

http://docs.oracle.com/cd/E11882_01/server.112/e18951/asmdiskgrps.htm#OSTMG13790

Regards,
Oscar

On Thu, May 21, 2015 at 11:46 PM, <Jay.Miller_at_tdameritrade.com> wrote:

> Hot spot rebalancing was part of the Oracle marketing presentation just
> before ASM came out. Someone must have eventually convinced the marketing
> department it didn’t do that because they stopped talking about it.
>
>
>
> Jay Miller
>
> Sr. Oracle DBA
>
> 201.369.8355
>
>
>
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Chris Taylor
> *Sent:* Wednesday, May 20, 2015 12:15 PM
> *To:* lawrence.malcolm_at_gmail.com
> *Cc:* oracle-l-freelists
> *Subject:* Re: ASM rebalancing
>
>
>
> For some reason, many of us (myself included) used to think ASM moved hot
> blocks to different areas to smooth out performance. This was a myth but
> I'm unsure of the origin.
>
> I know it started many years ago however and I was disabused of the notion
> some time ago.
>
>
>
> The only rebalancing ASM does is when you add or remove disks and data has
> to be moved/rebalanced based on percentages used of each device in the disk
> group. Has nothing to do with block usage.
>
>
>
> Regards,
> Chris
>
>
>
> On Wed, May 20, 2015 at 11:00 AM, Malcolm Lawrence <
> lawrence.malcolm_at_gmail.com> wrote:
>
> All,
>
>
>
> Does ASM move hot spots around in the background, or do you have to do a
> rebalance accomplish that?
>
>
>
> I cannot find anywhere in Oracle documentation stating that it does, so I
> assume that that it does not.
>
>
>
> Malcolm Lawrence
>
>
>

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Received on Fri May 22 2015 - 06:55:42 CEST