Installation guide

18
■ If the value of any kernel parameter is different from the recommended value,
then complete the following steps:
1. Using any text editor, create or edit the /etc/sysctl.conf file, and add or edit
lines similar to 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 = 1048576
By specifying the values in the /etc/sysctl.conf file, they persist when you
restart the system. However, on SUSE Linux Enterprise Server systems, enter
the following command to ensure that the system reads the
/etc/sysctl.conf
file when it restarts:
# /sbin/chkconfig boot.sysctl on
2. Enter the following command to change the current values of the kernel
parameters:
# /sbin/sysctl -p
Review the output from this command to verify that the values are correct. If
the values are incorrect, edit the /etc/sysctl.conf file, then enter this command
again.
3. Enter the command /sbin/sysctl -a to confirm that the values are set
correctly.
4. On SUSE systems only, enter the following command to cause the system to
read the
/etc/sysctl.conf file when it restarts:
file-max # /sbin/sysctl -a | grep file-max
ip_local_port_
range
# /sbin/sysctl -a | grep ip_local_port_range
rmem_default # /sbin/sysctl -a | grep rmem_default
rmem_max # /sbin/sysctl -a | grep rmem_max
wmem_default # /sbin/sysctl -a | grep wmem_default
wmem_max # /sbin/sysctl -a | grep wmem_max
Note: Include lines only for the kernel parameter values 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
minimum value, then specify the larger value.
Parameter Command