Tuning considerations for the Linux kernel when running Ceph

Tune the operating system, specifically for limits and memory allocation.

Production IBM Storage clusters generally benefit from tuning the operating system, specifically around limits and memory allocation. Ensure that adjustments are set for all hosts within the storage cluster. For more guidance, contact IBM Support.

Increasing the file descriptors

The Ceph Object Gateway can hang if it runs out of file descriptors. You can modify the /etc/security/limits.conf file on Ceph Object Gateway hosts to increase the file descriptors for the Ceph Object Gateway.
ceph       soft    nofile     unlimited

Adjusting the ulimit value for large storage clusters

Create a /etc/security/limits.d/50-ceph.conf file on each host that runs administrative commands, when running Ceph administrative commands on large storage clusters. An example of a large storage cluster is one with 1024 or more Ceph OSDs.
Note: The root user’s ulimit value is already set to unlimited by default on Red Hat Enterprise Linux.
Include the following contents to the configuration file:
USER_NAME       soft    nproc     unlimited

Replace USER_NAME with the name of the non-root user account that runs the Ceph administrative commands.