Re: RAID10 config...

"Brian Peasland" <dba_at_remove_spam.peasland.com> schrieb im Newsbeitrag news:3F95A1B0.A559D526_at_remove_spam.peasland.com...
> If you already have this system set up, then can you look at your I/O
> stats to see how busy things are? You'll have to go to the OS level to
> get I/O stats on the drives that have your redo, archivelogs,
> controlfiles.

Will do. Right now I just have a situation where a load creates way more activity on the redo disks than on the data disks and the cpu isn't loaded very much either.

It's only that before I try to reconfigure our SCSI controller to stripe the redos across four disks I'd like to know whether other people have striped the redos across several disks and have noticed a performance improvement even when writing small amounts of data during each write.

> > Am I right in assuming that during writes, controlfiles
> > become bottlenecks?
>
> My control files are the biggest bottleneck, not even close. Online redo
> logs, archive log destination, and the datafiles belong the the
> tablespace being loaded are the ones that get the most activity when I
> do mass loads of data.

I assume you meant to say that your controlfiles are *not* a bottleneck? That would be great because then I could put one on the volume with the datafiles.

> > Also log file sync and log file parallel write together take up 55%
> > of the % total elapsed time in the top 5 timed events of my
> > statspack report. (db file parallel write are another 13%)
>
> Another indicator that your redo logs are getting hit pretty heavily.
>
> > The problems I see are basically, how to distribute the controlfiles
> > and how to make redo writes faster, given 8 disks.
>
> Get more disks!! LOL. Why can't you hang more disks on your system?
It was a long enough fight to get a server with 8 disk slots when our whole database would fit on one disk. It was another long and hard fight to get the disks paired instead of put into one big raid5. I'll be shot for even thinking about another rack just for a bunch of disks.

Lots of Greetings!
Volker Received on Wed Oct 22 2003 - 05:25:05 CDT