Dynamic pagepool configuration
The dynamic pagepool feature is disabled by default. To enable it, the dynamicPagepoolEnabled parameter must be set to yes, and restart IBM Storage Scale on the node.
The following configuration parameters are available to adjust the size of the dynamic pagepool:
- pagepoolMinPhysMemPct
- Specifies the smallest possible size of the dynamic pagepool as a percentage of the node memory.
- pagepoolMaxPhysMemPct
- Specifies the largest possible size of the dynamic pagepool as a percentage of the node memory.
- pagepoolChangeGracePeriod
- Specifies the grace period in seconds between attempts to increase the pagepool.Note: When the dynamic pagepool feature is enabled on nodes that have more than 16 GiB of memory, the Linux configuration setting, vm.max_map_count, must be increased, according to the total memory installed. The appropriate value of vm.max_map_count can be determined by dividing the total memory size in bytes by 256 KiB . For example, on a node with 512 GiB of memory, the appropriate value is 2097152, which is the result of 549755813888 divided 262144. The vm.max_map_count value can be set by using the Linux sysctl command, for example, sysctl vm.max_map_count=2097152. To keep this change when the node is rebooted, update the /etc/sysctl.conf file.
- For more information about these parameters, see the mmchconfig command in the IBM Storage Scale: Command and Programming Reference Guide.
- For more information, see the Dynamic pagepool section in the IBM Storage Scale: Concepts, Planning, and Installation Guide.