Re: Questions on ASM best practices
Date: Wed, 17 Dec 2014 11:16:13 -0500
Message-ID: <CA+fnDAZMiOJUQ6OQRBPuHmnyfCus-9o2ga5i5g=zESOMyiGT_A_at_mail.gmail.com>
On Wed, Dec 17, 2014 at 10:23 AM, Stefan Koehler <contact_at_soocs.de> 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 -- http://www.freelists.org/webpage/oracle-lReceived on Wed Dec 17 2014 - 17:16:13 CET