Changing Kernel Parameter Values
Use these instructions to display and change the kernel parameter values if they are different from the minimum recommended value.
Use the following commands to display the current values of the kernel parameters:
Table A-2 Commands to Display Kernel Parameter Values
Parameter | Command |
---|---|
semmsl, 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 shm This command displays the details of the shared memory segment sizes. |
file-max | # /sbin/sysctl -a | grep file-max This command displays the maximum number of file handles. |
ip_local_port_range | # /sbin/sysctl -a | grep ip_local_port_range This command displays a range of port numbers. |
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 |
aio-max-nr | # /sbin/sysctl -a | grep aio-max-nr |
If you used the Oracle Preinstallation RPM to complete you preinstallation configuration tasks, then the Oracle Preinstallation RPM sets these kernel parameters for you. However, if you did not use the Oracle Preinstallation RPM or the kernel parameters are different from the minimum recommended value, then to change these kernel parameter values:
-
If you used the Oracle Preinstallation RPM, then your kernel parameter settings reside in the
/etc/sysctl.d/99-oracle-database-server-19c-preinstall-sysctl.conf
file. -
Include lines only for the kernel parameter values to change. For the semaphore parameters (kernel.sem), you must specify all four values. If any of the current values are larger than the minimum value, then specify the larger value.
-
The
/etc/sysctl.conf
file has been deprecated. -
Avoid setting kernel parameter values in multiple files under
/etc/sysctl.d/
. The file with a lexically later name under/etc/sysctl.d/
takes precedence, followed by/etc/sysctl.conf
. Oracle recommends that you use the Oracle Preinstallation RPM which, among other preinstallation tasks, also sets the kernel parameter values for your database installation.See Also:
sysctl.conf(5)
andsysctl.d(5)
man pages for more information
Parent topic: Configuring Kernel Parameters for Linux