Not enough memory HP-UX 11.0

[Tom Sepka]

I have a little problem. I have a K class server with 4GB memory and I am trying to two DBs. The one starts fine, but when the second one goes to startup I receive a not enough memory error. The DBs have separate oracle home and they run under serparate user accounts.

I understand that individually the Oracle SGA's cannot exceed 1.75 gb, but it does not follow in my mind (as feeble as it is) that I cannot have multiple DB's running with SGA's from different Oracle Homes, each SGA under the 32bit limit, and do something like the following:

USER SGA
oracle 1gb
oraprod 1gb
oratest 1gb

Oracle Support says that the combined SGA's cannot exceed 1.75gb. If that is the case why would anyone buy more than 2gb of RAM. This does not make sense. No one user (or codeset is using a shared memory greater than 1GB). If this can be done, please let us know what kernal parms we need to set to make it happen.

I would greatly appreciate someones help on this one.

Thanks,
Tom

[Patrick Wallek]

Have a look at this doc in the TKB:
http://us-support2.external.hp.com/cki/bin/doc.pl/sid=e5908d740c58852e3b/screen=ckiDisplayDocument?docId=200000024646318

It sounds like the problem you are having is that you are running 32 bit Oracle and that is limited to 1.75GB SGA. If you are running 32 bit Oracle, can you convert to 64 bit Oracle?

[Tom Sepka]

I understand that, but we are running with multiple oracle homes with each having its own binaries. I could understand if we were running multiple instances with one oracle home.

[John Poff]

Tom,

The problem is that you are running a 32 bit version of Oracle and HP-UX. This limits you to a 1.75TB shared memory segment. If you need more memory than that, you'll need to run 64 bit Oracle and HP-UX. It's not a question of having separate Oracle homes, binaries, or even separate Oracle user accounts. It's a question of addressing the memory space with a 32 bit limitation. I agree that if everything was 32 bit, there wouldn't be much need to buy more than 2 Gb of RAM. That is a reason why 64 bit computing is important.

The excellent book "HP-UX Tuning and Performance" by Robert F. Sauers and Peter S. Weygant explains it completely. Go buy the book. It is worth every penny.

JP

[Robert P Jessie]

Tom - they are correct! I had to upgrade to 64 bit Oracle! Then it used the memory in a different "quadrant". Don't ask me what that means.

[Ajay Sishodia]

Tom,

what you need is memory windows. Change the kernel parameter "max_mem_window" to a non-zero value. I would have max_mem_window= # of dbs + 1

Also edit /etc/services.window file like this

db1 100
db2 110
.....

please take a look at http://us-support2.external.hp.com/cki/bin/doc.pl/sid=6ba36edd0a04798c82/screen=ckiDisplayDocument?docId=200000048912928

[Ajay Sishodia]

Tom

you will need to restart oracle dbs, including the listener after doing the above. you can look at /usr/share/doc/mem_wndws.txt
on your server for details.

later
Ajay

[Ajay Sishodia]

Tom

you will need to restart oracle dbs, including the listener after doing the above. you can look at /usr/share/doc/mem_wndws.txt
on your server for details. You do not really need to upgrade to 64bit oracle.

later
Ajay