This forum is currently locked. You can't register or post questions at this time. (read more)

Oracle not releasing memory resources

All posts relating to Oracle database administration.

Moderator: Tim...

aunshakeel
Member
Posts: 35
Joined: Tue May 05, 2009 6:38 am

Oracle not releasing memory resources

Postby aunshakeel » Tue Jan 08, 2013 4:28 pm

Hi all,
I am using oracle 10.2.0.3 RAC on two HP RX3600 servers.
Each server had 16GB memory.
MY SGA size on each node is 9GB.
The momery utilisation on each node showed 99% used.
LAst night i increased the memory of both servers to 24GB.
Node 2 was showing 60% memory utilisation.
But node 1 is still showing 99% memory used.
After implementing the new RAM the only thing that happened on node 1 was the daily scheduled backup.
As soon as the backup started the memory rose to 99% but it has been almost 6 hours since the backup finished and it is still showing 99% used.
Is there a fix for this????
Thank you.

Tim...
Site Admin
Posts: 18437
Joined: Mon Nov 01, 2004 5:56 pm
Location: England, UK
Contact:

Re: Oracle not releasing memory resources

Postby Tim... » Tue Jan 08, 2013 5:11 pm

Hi.

Well, you've not actually said what is using the memory. You know that the SGA is only using 9G. You've not said what size your PGA is. You've also not said how much memory is being used by non-Oracle processes.

One thing that might be tricking you is the file system cache. Most operating systems, including HP-UX use free memory as file system cache, releasing it when it is needed for something real. As a result, heavy file usage can make the system appear to be using more memory than it actually is. Most OSes give you a way to identify what is real memory usage and what are buffers for the file system cache. On Linux the command is "free". Not sure what it is in HP-UX. I guess glance will show you???

Cheers

Tim...
Tim...
Oracle ACE Director
Oracle ACE of the Year 2006 - Oracle Magazine Editors Choice Awards
OakTable Member
OCP DBA 7.3, 8, 8i, 9i, 10g, 11g
OCP Advanced PL/SQL Developer
Oracle Database: SQL Certified Expert
My website: http://www.oracle-base.com
My blog: http://www.oracle-base.com/blog

aunshakeel
Member
Posts: 35
Joined: Tue May 05, 2009 6:38 am

Re: Oracle not releasing memory resources

Postby aunshakeel » Tue Jan 08, 2013 5:38 pm

Thank you Mr. Tim for your reply,
What processes are hogging up my server is my confusion also ... AS i mentioned as soon as the backup started the memory rose from 60% to 99% and never got released again. The PGA size is 600MB. Besides all the top processes running are related to oracle background processes. is thereany way to check this file system cache.

Tim...
Site Admin
Posts: 18437
Joined: Mon Nov 01, 2004 5:56 pm
Location: England, UK
Contact:

Re: Oracle not releasing memory resources

Postby Tim... » Tue Jan 08, 2013 5:48 pm

Hi.

As I said, I don't know what the command is on HP-UX. A quick Google suggest swapinfo should provide the information, but I don't know for certain.

Cheers

Tim...
Tim...
Oracle ACE Director
Oracle ACE of the Year 2006 - Oracle Magazine Editors Choice Awards
OakTable Member
OCP DBA 7.3, 8, 8i, 9i, 10g, 11g
OCP Advanced PL/SQL Developer
Oracle Database: SQL Certified Expert
My website: http://www.oracle-base.com
My blog: http://www.oracle-base.com/blog


Return to “Oracle Database Administration”

Who is online

Users browsing this forum: No registered users and 4 guests

cron