Re: Questions on ASM best practices

  • From: Jeremy Schneider <jeremy.schneider@xxxxxxxxxxxxxx>
  • To: Stefan Koehler <contact@xxxxxxxx>, "Amir.Hameed@xxxxxxxxx" <Amir.Hameed@xxxxxxxxx>
  • Date: Wed, 17 Dec 2014 11:16:13 -0500

On Wed, Dec 17, 2014 at 10:23 AM, Stefan Koehler <contact@xxxxxxxx> wrote:
>>> Remember that ASM will automatically use the smaller stripe size for redo 
>>> logs; you don't have to configure that.
>
> Unfortunately not anymore. This changed with 11.2, but the documentation does 
> not keep up with it. The default for redo log files is COARSE nowadays
> as well.

oops, seems I didn't notice that change!  thanks for pointing this out

the documentation actually does keep up...
11gR1: 
http://docs.oracle.com/cd/B28359_01/server.111/b31107/asmfiles.htm#g2223792
11gR2: 
http://docs.oracle.com/cd/E11882_01/server.112/e18951/asmfiles.htm#g2223792

also, i don't know what engineer wrote Doc ID 1269158.1 (Redo Log
Striping In 11.2 ASM, is Coarse Or Fine?) but it has an interesting
take on the change, suggesting that the larger stripe size is more
optimal for redo logs in most cases because "disk track sizes" are
closer to 1MB than 128k on modern storage.  I'm not sure I buy the
exact wording there - but I do think this change was probably made
carefully;11gR2 was a big release for ASM (rolling it into the grid
home) and I'd suspect that the new defaults probably do make sense for
most cases.

-J

--
http://about.me/jeremy_schneider
--
//www.freelists.org/webpage/oracle-l


Other related posts: