Hi Oracle - AIX experts, I am in very difficult situation. We have AIX 7.1 TL3SP1 server in PureFlex hardware. On this AIX we have Oracle DB 11.2.0.4.0. DB works as expected after startup and suddenly it goes crazy. No one can connect to this DB from application and there is a lot of error in alert log and also in AIX. So this is heavy swapping problem which I had previously in Oracle Linux , in that case we added memory and swap[ file also we had problem with low disks (actually the problem was problematic disks). Here we have 8G memory and 16G page space and disks also OK. The only thing in which I am not sure the configuration of page spaces. But I am not AIX specialist.... Please who have same experience with this , please advise how can we solve this. root@sgp-podb201a/ # lsps -a Page Space Physical Volume Volume Group Size %Used Active Auto Type Chksum paging01 hdisk6 vg01 8192MB 1 yes yes lv 0 paging00 hdisk1 vg01 8192MB 4 yes yes lv 0 hd6 hdisk0 rootvg 512MB 0 no no lv 0 Info MEMORY Real,MB 8192 % Comp 64 % Noncomp 16 % Client 16 PAGING SPACE Size,MB 16384 % Used 2 % Free 98 PAGING Faults 25 Steals 0 PgspIn 0 PgspOut 0 PageIn 0 PageOut 15 Sios 15 Alert log Tue Jun 24 08:20:32 2014 WARNING: Heavy swapping observed on system in last 5 mins. pct of memory swapped in [359.98%] pct of memory swapped out [0.87%]. Please make sure there is no memory pressure and the SGA and PGA are configured correctly. Look at DBRM trace file for more details. Tue Jun 24 08:37:52 2014 Emon ping encountered error 4021 Errors in file /opt/oracle/diag/rdbms/shpsgpp1dg1/SHPSGPP1/trace/SHPSGPP1_q000_20185316.trc: ORA-04021: timeout occurred while waiting to lock object Tue Jun 24 09:00:53 2014 Emon ping encountered error 4021 ******* ORA-04021: timeout occurred while waiting to lock object Tue Jun 24 12:35:16 2014 Emon timeout encountered error 4021 Tue Jun 24 12:35:16 2014 Emon timeout encountered error 4021 ********** Oracle trace file *** 2014-06-24 13:13:31.648 *** SESSION ID:(478.11) 2014-06-24 13:13:31.648 *** CLIENT ID:() 2014-06-24 13:13:31.648 *** SERVICE NAME:(SYS$BACKGROUND) 2014-06-24 13:13:31.648 *** MODULE NAME:(Streams) 2014-06-24 13:13:31.648 *** ACTION NAME:(QMON Slave) 2014-06-24 13:13:31.648 KSV 4021 error in slave process *** 2014-06-24 13:13:31.648 ORA-04021: timeout occurred while waiting to lock object OPIRIP: Uncaught error 447. Error stack: ORA-00447: fatal error in background process ORA-04021: timeout occurred while waiting to lock object Thanks in advance. *-----------------* *Tiran* *Best RegardsStay in touch...*