AMM changes in 11.2.0.3?
937685May 16 2012 — edited May 16 2012We are doing some testing on a server with 32GB of RAM running Oracle Enterprise Linux v5.4 (2.6.18-194.el5). Our baseline test, using 11.2.0.1, had /dev/shm sized at 24GB and memory_target set at 24GB. This test had no problems and we saw no swapping at all (si/so in vmstat... monitoring our swap partition with iostat). We then wiped that installation and installed 11.2.0.3, set our parameters just like we did on 11.2.0.1, and imported our data. Now after we are running a reporting workload for about 10 minutes, the system starts swapping to the point that it thrashes the disk. I've been hunting through release notes and readmes and I can't seem to find any documented changes to AMM w/ 11.2.0.3.
We see only about 12GB of data in /dev/shm, but we see 20+GB of data on the individual running oracle processes on Linux (using pmap).
Why are the same AMM settings causing swapping on 11.2.0.3 when they worked fine on 11.2.0.1? Are there new parameters that we need to be modifying? We even toned down memory_target and memory_max_target to 18GB but we still end up swapping.