Re: Redo Log Positioning

IMO you have no other choice than to place the redologs on one raid 1 disk, and the hard- or software mirror on the other raid 1 disk. As the redolog files are written sequentially there is no performance hit in placing all three on one drive. I usually start with 4 redo log groups, this layout seems less troublesome.

Hth,

Sybrand Bakker, Oracle DBA

<rogerxb_at_my-deja.com> schreef in berichtnieuws 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