Set lock_sga to true on Linux (SLES)
To lock the SGA into physical memory you have to set the lock_sga parameter to true.
Usually you get following Error message.
SQL> startup
SQL> ORA-27102: out of memory
Linux-x86_64 Error: 12: Cannot allocate memory
The problem it ulimit -l
You have to set it in /etc/security/limits.conf and relogon to the system and restart database.
cat /etc/security/limits.conf
...
oracle soft memlock unlimited
oracle hard memlock unlimited
alter system set lock_sga=true scope=spfile;
shutdown immediate
startup
And you SGA stays in physical memory.
If you SGA gets pages out you will encounter following waits.
Wait Event: latch: shared pool
On Linux if you want to lock sga into physical memory,it is recommended that you set huge page.
Comment by mq44944 — August 17, 2010 @ 8:36 am
thank you for good information. thank you.*^^*
Comment by Soohee — April 20, 2012 @ 10:07 am