Re: Separate ASM disk group for online redo log files?
From: Steve Howard <stevedhoward_at_gmail.com>
Date: Mon, 11 Apr 2011 05:00:16 -0700 (PDT)
Message-ID: <eb513d33-f8c0-41cc-b813-7638d5d9754f_at_d28g2000yqc.googlegroups.com>
On Apr 11, 4:05 am, mhoys <matthias.h..._at_gmail.com> wrote:
> Ok, I've read a lot about ASM recently :-)
>
> In one of the technical papers from Oracle, they recommend to have
> only 2 disk groups: one for the data files, and one for the recovery
> files (FRA). This means that the online redo log files are included in
> the disk group for the data files, but I wonder if this is a set-up
> that is followed by most DBA's? I would think that, for performance
> reasons, it's best to create a separate third disk group for the
> online redo log files? How do you guys do it? :-)
>
> Thanks,
> Matthias
Date: Mon, 11 Apr 2011 05:00:16 -0700 (PDT)
Message-ID: <eb513d33-f8c0-41cc-b813-7638d5d9754f_at_d28g2000yqc.googlegroups.com>
On Apr 11, 4:05 am, mhoys <matthias.h..._at_gmail.com> wrote:
> Ok, I've read a lot about ASM recently :-)
>
> In one of the technical papers from Oracle, they recommend to have
> only 2 disk groups: one for the data files, and one for the recovery
> files (FRA). This means that the online redo log files are included in
> the disk group for the data files, but I wonder if this is a set-up
> that is followed by most DBA's? I would think that, for performance
> reasons, it's best to create a separate third disk group for the
> online redo log files? How do you guys do it? :-)
>
> Thanks,
> Matthias
No, we separate them into a separate smaller disk group. Granted, this is on a database that generates 400GB on average per day of archived redo logs (and as high as 1.5TB). However, we were getting killed with checkpointing, so when we moved them to a separate diskgroup, the problem went away.
As time goes on, I think Oracle tries to make things too simple for DBA's sometimes, and they ignore physics in the process :) Received on Mon Apr 11 2011 - 07:00:16 CDT