Re: LINUX Kernel Parameters

"Dave Hau" <davehau-no-spam-123_at_no-spam.netscape.net> wrote in message news:<R6HHa.3708$eQ3.3579_at_newssvr19.news.prodigy.com>...
> "Brian Peasland" <oracle_dba_at_remove_spam.peasland.com> wrote in message
> news:3EEF334A.A5DCB6F2_at_remove_spam.peasland.com...
> > I run multiple instances on a server all the time, without problems.
> > Tuning can be a bit of a pain when you have to account for more than one
> > instance using a resource, but most of the tuning efforts are focused on
> > the application and SQL statements.
> >
> > To answer your question why I would run more than one instance on one
> > server, I'd ask why would you ever run more than one instance at all?
>
> Running more than one instance for a database is fine, just not on the same
> machine. You do that for clustering, i.e. for load-balancing and failover
> (RAC).
>
> In the case of running a development server and a production server on the
> same machine, can you not run a single instance of Oracle but have different
> schemas for dev vs. production?

One of the main reasons for using different instances is different backup requirements. Yes, you can backup by tablespace, but another reason is development often does weird things and you don't want to crash your production instance, or otherwise have to bounce it. Of course, even with the instances on different boxes I've still seen people do stuff to the wrong instance, sigh...

To the OP, there are some enlightening documents on http://metalink.oracle.com regarding multiple instances and SGA and what all the unix-centric stuff is.

>
> Cheers,
> Dave
>
>
>
>
> > Why not throw all of your applications in one gigantic instance? I have
> > some servers which run multiple instances to support multiple
> > applications, normally running different Oracle versions. I have some
> > projects which can't afford a development server and a production server
> > so we run multiple instances on the same server. It's not my idea, but
> > you work with what you have. Running a business doesn't always allude to
> > "perfection" in one's configuration.
> >
> > Cheers,
> > Brian
> >
> > Dave Hau wrote:
> > >
> > > You can *install* more than 1 instance on the same machine, but at any
> given
> > > time, you're only going to *run* one instance I assume. Why would you
> ever
> > > want to run more than 1 instance of Oracle on the same machine?
> > >
> > > Have a look at:
> > >
> > >
> http://asktom.oracle.com/pls/ask/f?p=4950:8:312574728443032111::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:7739845026791,
> > >
> > > Cheers,
> > > Dave
> > >
> > > "Andy" <andybush2003_at_yahoo.com> wrote in message
> > > news:bb3692fe.0306161357.344d5ac_at_posting.google.com...
> > > > Hi,
> > > >
> > > > OS: Red Hat Advanced Server 2.1
> > > > DB: Oracle 9.2
> > > >
> > > > I followed the instructions in the installation manual, and was able
> > > > to install the 9.2 database. My question is that after having created
> > > > the 1st instance, I would like to add additional instances.
> > > >
> > > > The installation document only gives the kernel parameter values for
> > > > one instance. Should I simply multiply the values by number of
> > > > instances and adjust the values upwards.
> > > >
> > > > I know UNIX enough to find my way around, however not to the level as
> > > > to make sense of how and what effects these kernel parameters would
> > > > have on database processing on LINUX.
> > > >
> > > > Any help would be really appreciated.
> > > >
> > > > Thanks
> >
> > --
> > ===================================================================
> >
> > Brian Peasland
> > oracle_dba_at_remove_spam.peasland.com
> >
> > Remove the "remove_spam." from the email address to email me.
> >
> >
> > "I can give it to you cheap, quick, and good. Now pick two out of
> > the three"

jg

--
@home.com is bogus.
Charlie Parker, oh yeah.