Re: Redo Log Positioning

Create two new log groups (3 and 4) on RAID1 (mirror) containing of 1 member each and then remove the redo log group 2 from RAID5. So you will have 3 redo log groups at 2 members each: the system will create and maintain the second "members" on mirror drive for you. Or you can break the mirror and add second redo log members manually from Oracle. It is advisable for better performance to allocate redo logs onto raw disk partitions/slices because of sequentially-written nature of the redo logs. You also need to increase the size of redo log files if the database statistics indicates wait events for the archiver process.

Eugene.

<rogerxb_at_my-deja.com> wrote in message news:8emjtg$t78$1_at_nnrp1.deja.com...
> I currently have two redo log files, unmirrored and sized at 2M each.
> When we see intense processing there is a slow down and the error log
> indicates that the bottleneck is the redo logs; they are unable to
> complete archiving quickly enough when switching from redo 1 to redo 2.
>
> So I realize I have to re-work the system to at least increase the size
> of the logs, and therefore switch less frequently.
>
> Here's my question.
>
> I have 5 physical 9.1 Gig drives - split into two raid sets -
> 2 * 9.1 Gig Raid 1 and
> 3 * 9.1 Raid 5.
> The current redo logs are placed one on each of these separate
> devices.
> I understand that my Raid 5 is going to be slower when writing the
> logs, but what I want to know is - how should I lay out my log files?
> I believe The theoretical best is to have three groups with two
> mirrored members in each, across at least three devices; but I only
> have two physical devices and one is quicker than the other ...... any
> suggestions ??
> Should I just increase the size of my logs, and allow the operating
> system to do all the mirroring ???
>
> Cheers
> Rog
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
Received on Tue May 02 2000 - 00:00:00 CDT