RE: Mirroring redo log groups or not ?

From: Crisler, Jon <>
Date: Tue, 7 Apr 2009 13:14:12 -0400
Message-ID: <56211FD5795F8346A0719FEBC0DB0675041A7BC1_at_mds3aex08.USIEXCHANGE.COM>

The redo logs are 6 groups, 2 members each, 1gb in size. The SAN is EMC Clariion. Raid 5 does have somewhat poorer performance in writes in our environment but its usually not a major factor.

-----Original Message-----
From: Rajeev Prabhakar [] Sent: Tuesday, April 07, 2009 12:48 PM
To: Crisler, Jon
Cc: Oracle-L Freelists
Subject: Re: Mirroring redo log groups or not ?

Hello Jon,

Before you go into redesign of the redo logs, did you check w/the SAs/Storage
Admins ? During my last interactions with type of performance issue, I found
that RAID 5 had a negative effect on overall performance during QA testing. of
course, your mileage may vary.

Can you share your findings (as seen by SA/Storage Admins). How big are your
redo logs ? What kind of disks (Storage/SAN) are you folks using ?


On Tue, Apr 7, 2009 at 12:16 PM, Crisler, Jon <> wrote:

> So, if the LUN that holds the online redo logs is already protected
(raid 1,
> 5 etc) do I really need to mirror the online redo logs ? Should I
> the LUN to Raid 1 / 0 ? if I convert to Raid 1/ 0 should I keep redo
> mirroring and point to the same LUN ?

Received on Tue Apr 07 2009 - 12:14:12 CDT

Original text of this message