Re: Can OFA and multiple instances lead to DBWR contention

In a perfect, budget-free world, yes. Because *any* activity on Instance/Database A is likely to compete with any activity on Instance/Database B for server resources.

Whether the competition is serious enough to warrant the added expense and maintenance effort involved is up to you, the Senior Oracle DBA, to evaluate and work out.

There is also the question of eggs and baskets: if your server power supply dies, you have multiple Instances taken out at the same time. Distribute them around multiple boxes, and you might lose 1, but not the lot. Is that an issue? That's what Senior DBAs are there to work out for their own particular environments.

Regards
HJR "John Jones" <john.jones_at_duke.edu> wrote in message news:9j99jg$3ks$1_at_news.duke.edu...
> Please expand on that thought. Why would numerous SIDs be a VERY BAD
> IDEA.???
> We have IBM's M80 servers. They have multiple processors, 8 Gig of RAM,
 and
> configured on Shark disk. One instance on this server would have little
 to
> no load on it. On some of our smaller servers we have multiple instances
> because they are either small or have very little activity. Are you
 saying
> each of these should also be on seperate servers????
>
> --
> John Jones
> Senior Oracle DBA
> Duke University, OIT
> john.jones_at_duke.edu
> "Sybrand Bakker" <postbus_at_sybrandb.demon.nl> wrote in message
> news:tle4mtt4qgl619_at_beta-news.demon.nl...
> >
> > "Akinwande Seigmund Walter-Johnson III" <asjohns_at_midway.uchicago.edu>
 wrote
> > in message news:8dE57.65$_4.4568_at_news.uchicago.edu...
> > > All,
> > > Running multiple instances on one machine and using OFA requires that
 all
> > > data for all instances be written to
> > > one or more disk's dedicated for data.
> > > Couldn't contention arise between all DBWR's for the numerous SID's ?
> > >
> > >
> > >
> >
> > Numerous SIDs on one server are a VERY BAD IDEA anyway, OFA or no OFA.
> >
> > Regards,
> >
> > Sybrand Bakker, Senior Oracle DBA
> >
> >
> >
>
>
Received on Tue Jul 24 2001 - 04:30:40 CDT