I heard that activating DIRECT_IO helps solve the RMAN memory eating problem on kernels 2.4.
On http://dbasolutions.wikispaces.com/RMAN+Performance+Tuning you can see some ideas on how to tune rman memory usage. To show your Oracle DBA's that more memory is less performance, ask them to try the "Mainframe Way". Get some heavy queries, get them to run them using the current configuration. Run it 3 or 4 times. Get the average running time. Change a couple parameters: - Use SGA max size = 66% of available memory - Use 4GB on the guest - Use DIRECT_IO - Use at least 40 io slaves Run again 4 times. Compare the results. The last time I did this, we got a 39 min job running in 9 minutes. The DBA laughed on me, saying I crashed Oracle and the queries died. He opened the results table, everything was correct. He got angry, started again the queries. 9 minutes. He did it again, 9 minutes again. And I spent the next hour explaining why a mainframe is not a x86 box... Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/10/2 tony egan <[email protected]> > The kernel version that you are using supports cgroups - > > https://www.suse.com/releasenotes/s390x/SUSE-SLES/11-SP1/#ResourceManagement > and > has it enabled by default (if the memory cgroups feature is not needed, it > can be switched off by passing cgroup_disable=memory on the kernel command > line, reducing memory consumption of the kernel a bit.) > > Perhaps a memory cgroup could help in this situation? > > > > > On Wed, Oct 2, 2013 at 8:01 AM, van Sleeuwen, Berry < > [email protected]> wrote: > > > True, knowing what buttons to push and what dials to turn might help too > > :-). > > > > We know the memory and swap are exhausted, and we know the rman processes > > are the ones that cause it. So now we have to resolve that. I would like > to > > have rman use less memory but I'm not quite sure if and how we can > achieve > > that. > > > > As a temporary measure we can add a swap disk. That still doesn't lower > > memory usage for rman but at least it might prevent the OOM killer from > > being called. > > > > Regards, Berry. > > > > -----Original Message----- > > From: Linux on 390 Port [mailto:[email protected]] On Behalf Of > > Barton Robinson > > Sent: Wednesday, October 02, 2013 1:45 PM > > To: [email protected] > > Subject: Re: Oracle RMAN OOM > > > > > > Really good performance monitors would give you lots of good information. > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO LINUX-390 or > > visit > > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > ---------------------------------------------------------------------- > > For more information on Linux on System z, visit > > http://wiki.linuxvm.org/ > > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
