Re: How much instances per server?

"Volker Lauterfeld" <lauterfeld_at_cos-gmbh.de> wrote in message news:9edkif$olv$00$1_at_news.t-online.com...
> Hi!
>
> How much instances (SIDs) per physical server are possible to run at the
> same time?

There's no limit. (Well, no theoretical limit anyway). You are constrained only by the physical RAM on the machine and the sizes of the Instances you wish to create.

However, that is a stupendously bad way to go about things. Especially on Windows of any flavour, your Instances are likely to compete, not to mention Windows' penchant for paging out anything that moves.

> OS is Win2000 or WinNT, Oracle 8.1.7 or higher. Standard SGA about
 30-40MB.
> The Hardware will be the best of the best (unlimited RAM, enough hard
 disks
> with state of the art LVD, multi cpu, gigabit network adapter, and so
 on...)
> The goal is to place as much instances as possible on one server.
> Performance is secondary.

I doubt it will remain so for very long. But what's the *real* issue you're trying to address? Different applications, but not enough money for one box per application (which is the extremely expensive ideal)? You could house multiple applications within the one database, separated into different schemas, but then if one Instance fails, the whole lot goes out of commission for the duration... so that's a terrible idea, too. Even going your route, one bit of OS instability, and a crashed box later, you've still lost the lot.

Depending on the number of applications, I'd still tend to think (off the top of my head, I admit) that several cheaper boxes running separate Instances & Databases would likely give a better combination of performance and robustness.

Regards
HJR
>
> I'm very interested in your opinion.
>
> Thanks in advance,
> Volker.
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Received on Tue May 22 2001 - 08:42:41 CDT