ipcs -s | grep oracle | awk 'print $2' | xargs -n1 ipcrm -s Linux :

SELECT value/1024/1024 MB FROM v$parameter WHERE name='sga_max_size'; Check free memory :

SHOW PARAMETER processes SHOW PARAMETER sessions Increase (e.g., to 2000):

oracle soft nproc 16384 oracle hard nproc 32768 oracle soft nofile 65536 oracle hard nofile 65536 in /etc/system :

# Current limits cat /proc/sys/kernel/shmmax cat /proc/sys/kernel/shmall Set for large SGA:

# Current semaphore limits (SEMMSL, SEMMNS, SEMOPM, SEMMNI) ipcs -ls | grep "max number of arrays" cat /proc/sys/kernel/sem Recommended for Oracle:

vi /etc/security/limits.conf Add:

ls -l $ORACLE_HOME/bin/oracle # Should have setuid (rwsr-s--x) chmod 6751 $ORACLE_HOME/bin/oracle Increase (Linux):

SEMMSL = 250 (or max processes per instance) SEMMNS = 32000 (or higher) SEMOPM = 100 SEMMNI = 256 (or 1024 for large systems) Set persistently:

set maxuprc=16384 , then verify:

ulimit -u Linux (check & set) :

echo "kernel.sem = 250 32000 100 256" >> /etc/sysctl.conf sysctl -p in /etc/system :

# shmmax = 80% of RAM, shmall = shmmax / 4096 (page size) echo "kernel.shmmax = 68719476736" >> /etc/sysctl.conf # 64GB echo "kernel.shmall = 16777216" >> /etc/sysctl.conf sysctl -p :

set semsys:seminfo_semmns=4096 set semsys:seminfo_semmni=1024 set semsys:seminfo_semmsl=512 (if instance is down):

Svr4 Error 11 Resource Temporarily Unavailable | Ora-27103 Internal Error