9.9 Configuring Kernel Parameter Settings for Oracle Linux Containers

If you specify the --privileged option with the lxc-oracle template script, you can adjust the values of certain kernel parameters for a container under the /proc hierarchy.

The container mounts /proc read-only with the following exceptions, which are writable:

  • /proc/sys/kernel/msgmax

  • /proc/sys/kernel/msgmnb

  • /proc/sys/kernel/msgmni

  • /proc/sys/kernel/sem

  • /proc/sys/kernel/shmall

  • /proc/sys/kernel/shmmax

  • /proc/sys/kernel/shmmni

  • /proc/sys/net/ipv4/conf/default/accept_source_route

  • /proc/sys/net/ipv4/conf/default/rp_filter

  • /proc/sys/net/ipv4/ip_forward

Each of these parameters can have a different value than that configured for the host system and for other containers running on the host system. The default value is derived from the template when you create the container. Oracle recommends that you change a setting only if an application requires a value other than the default value.

Note

Prior to UEK R3 QU6, the following host-only parameters were not visible within the container due to kernel limitations:

  • /proc/sys/net/core/rmem_default

  • /proc/sys/net/core/rmem_max

  • /proc/sys/net/core/wmem_default

  • /proc/sys/net/core/wmem_max

  • /proc/sys/net/ipv4/ip_local_port_range

  • /proc/sys/net/ipv4/tcp_syncookies

With UEK R3 QU6 and later, these parameters are read-only within the container to allow Oracle Database and other applications to be installed. You can change the values of these parameters only from the host. Any changes that you make to host-only parameters apply to all containers on the host.