Kernel Parameters

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Next, we need to check some kernel parameters. Run the following commands, check the output, and make the changes as required.

/sbin/sysctl -a | grep sem /sbin/sysctl -a | grep shm /sbin/sysctl -a | grep file-max /sbin/sysctl -a | grep ip_local_port_range

Output:

kernel.sem = 250 32000 100 128 kernel.shmmni = 4096 kernel.shmall = 2097152 kernel.shmmax = 2147483648 fs.file-max = 65536 net.ipv4.ip_local_port_range = 1024 65000

If you need to change any of the values, open up /etc/sysctl.conf in your favourite text editor (e.g., emacs21) and change the appropriate entries as follows:

kernel.shmall = 2097152 kernel.shmmax = 2147483648 kernel.shmmni = 4096 kernel.sem = 250 32000 100 128 fs.file-max = 65536 net.ipv4.ip_local_port_range = 1024 65000

Run /sbin/sysctl -p to apply the changes (only if you changed something of course.)

Add the following lines to /etc/security/limits.conf file:

* soft nproc 2047 * hard nproc 16384 * soft nofile 1024 * hard nofile 65536

Add (or un-comment) the following lines in /etc/pam.d/login and /etc/pam.d/su:

session required /lib/security/pam_limits.so

Because we are using the Bash shell add the following lines to the /etc/profile file:

if [ $USER = "oracle" ]; then if [ $SHELL = "/bin/ksh" ]; then ulimit -p 16384 ulimit -n 65536 else ulimit -u 16384 -n 65536 fi fi