Re: How many instances on a server?

David Van Zandt wrote:
>
> Hi, I need some way to determine how many instances I can run on a
> server (HP-UX N-class, dual processor). A related question, how might I
> judge how much SGA is consumed for all existing instances, and how much
> is left (for a new one)?
>
> TIA.
How many instances of what?
You mention SGA, so I suppose you're talking of the Oracle Shared Global Area,
is that right?
Well, the N-Class runs HP-UX 11.00 in 64bit mode. If you now use a Oracle
< 8.05, you have a total of 1.75 GB of shared memory available, because those Oracle versions are 32bit. Now it depends on the size of the instance(s)
you configure.
To calculate shared memory consumption by one Oracle database, connect via svrmgrl
as internal to your database and issue
SVRMGRL> show sga
this will give you a good overview of memory configuration for the specific instance.
If you have plenty of memory and are still using 32bit oracle, you might consider
the memory windowing feature, that will reserve 1 GB of shared memory to each Oracle
instance. If you don't want to fiddle around with memory windows, go on to Oracle 8.0.5
in 64bit version. Now you can address up to 8 TB of shared memory. Should be enough,
at least for the next two years :>)
Have a look at Memory Windows at:
http://www.docs.hp.com/hpux/os/#papers
Download the whitepaper "Memory Windows in HP-UX 11.0, White paper"

Greetings,
Thilo Received on Sun Nov 21 1999 - 11:11:41 CST