Re: Can OFA and multiple instances lead to DBWR contention

Between John and Howard can you asswer my question

"Howard J. Rogers" <howardjr_at_www.com> wrote in message news:3b5de159_at_usenet.per.paradox.net.au...
> You used the word "you" twice in your first paragraph. Does that mean you
> have a problem with the word "you"?
>
> HJR
>
> "John Jones" <john.jones_at_duke.edu> wrote in message
> news:9jk114$3si$1_at_news.duke.edu...
> > Seems that you have a problem with my title of "Senior Oracle DBA". You
> > reference it twice in your reply.
> >
> > You did make my point though. The blanket statement that multiple
 Instances
> > is a bad idea is just wrong. All databases are different, so you can
 not
> > just make blanket statements that a particular setup is right or wrong
 for
> > everybody. Each DBA has to be able to properly evaluate his/her own
 needs.
> >
> > As for the eggs and baskets, everything on our servers have backups. We
> > have multiple power supplies. Not saying that something could not
 happen
> > that causes complete failure, but we try. We have well over 100 Oracle
> > instanaces and there is no way to justify having one instance per
 machine.
> >
> >
> > John Jones
> > Senior Oracle DBA
> > Duke University, OIT
> > john.jones_at_duke.edu
> > "Howard J. Rogers" <howardjr_at_www.com> wrote in message
> > news:3b5d3fdc_at_usenet.per.paradox.net.au...
> > > 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 Wed Jul 25 2001 - 11:10:51 CDT