Shell Limits for Oracle User

To improve the performance of the Oracle software on Linux systems you must increase the following limits for the oracle user.

Item	Hard Limit	Description
nofile	65536	Maximum number of open file descriptors
nproc	16384	Maximum number of processes available to a single user

Linux

Perform following steps to increase the shell limits.

Verify current shell limit for nofile as root.

# ulimit –n
Verify current shell limit for nproc as root.

# ulimit –u

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

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

Add or edit the following line in the /etc/pam.d/login file, if it does not already exist.
1. session required /lib/security/pam_limits.so
Depending on the oracle user's default shell, make the following changes to the default shell start-up file. 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
umask 022
```

Create or edit the /etc/sysctl.conf file and add or edit the file with the following:

fs.aio-max-nr = 1048576
fs.file-max = 6815744
kernel.shmall = 2097152
kernel.shmmax = 536870912
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
net.ipv4.ip_local_port_range = 9000 65500
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048586