To view the current value specified for these kernel parameters, and to change them if necessary:

1. Enter commands similar to the following to view the current values of the kernel parameters:

   Note:

   Make a note of the current values and identify any values that you must change.

   ParameterCommandsemmsl, semmns, semopm, and semmni# /sbin/sysctl -a | grep sem

   This command displays the value of the semaphore parameters in the order listed.

   shmall, shmmax, and shmmni# /sbin/sysctl -a | grep shmfile-max# /sbin/sysctl -a | grep file-maxip_local_port_range# /sbin/sysctl -a | grep ip_local_port_rangermem_default# /sbin/sysctl -a | grep rmem_defaultrmem_max# /sbin/sysctl -a | grep rmem_maxwmem_default# /sbin/sysctl -a | grep wmem_defaultwmem_max# /sbin/sysctl -a | grep wmem_max

2. If the value of any kernel parameter is different from the recommended value, then complete the following steps:

   Using any text editor, create or edit the /etc/sysctl.conf file and add or edit lines similar to the following:

   
   

   Note:

   Include lines only for the kernel parameter values that you want to change. For the semaphore parameters (kernel.sem), you must specify all four values. However, if any of the current values are larger than the recommended value, specify the larger value.

   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 rmem_default = 262144 rmem_max = 262144 wmem_default = 262144 wmem_max = 262144

   By specifying the values in the /etc/sysctl.conf file, they persist when you restart the system.

   On SUSE systems only, enter the following command to ensure that the system reads the /etc/sysctl.conf file when it restarts:

   # /sbin/chkconfig boot.sysctl on

Set Shell Limits for the oracle User

To improve the performance of the software, you must increase the following shell limits for the oracle user:

Shell LimitItem in limits.confHard LimitMaximum number of open file descriptorsnofile65536Maximum number of processes available to a single usernproc16384

To increase the shell limits:

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

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

2. 
   

   Add the following line to the /etc/pam.d/login file, if it does not already exist:

   session required /lib/security/pam_limits.so

3. Depending on the oracle user's default shell, make the following changes to the default shell startup file:

   • For the Bourne, Bash, or Korn shell, add the following lines in the /etc/profile file (or the /etc/profile.local file on SUSE systems):

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

   • For the C shell, add the following lines in the /etc/csh.login file (or the /etc/csh.login.local file on SUSE systems):

     if ( $USER == "oracle" ) then limit maxproc 16384 limit descriptors 65536 endif

7 Creating Required Directories

Create directories with names similar to the following, and specify the correct owner, group, and permissions for them:

• The Oracle base directory

• An optional Oracle data file directory (optional)

The Oracle base directory must have 3 GB of free disk space, or 4 GB of free disk space if you choose not to create a separate Oracle data file directory.

Note:

If you do not want to create a separate Oracle data file directory, then you can install the data files in a subdirectory of the Oracle base directory. However, this is not recommended for production databases.

To create the Oracle base direct