Linux configuration considerations

Learn about the Linux® configuration that you need to consider during installation or configuration of IBM Storage Scale on your cluster.

Note: This information applies only to Linux nodes.
Depending on your system configuration, you need to consider the following points.
  1. Why can only one host successfully attach to the Fibre Channel loop and see the Fibre Channel disks?

    Your host bus adapter might be configured with an enabled Hard Loop ID that conflicts with other host bus adapters on the same Fibre Channel loop.

    To see whether that is the case, restart your machine and enter the adapter bios with <Alt-Q> when the Fibre Channel adapter bios prompt appears. Under the Configuration Settings menu, select Host Adapter Settings and either make sure that the Adapter Hard Loop ID option is disabled or assign a unique Hard Loop ID per machine on the Fibre Channel loop.

  2. Could the GPFS daemon be terminated due to a memory shortage?

    The Linux virtual memory manager (VMM) exhibits undesirable behavior for low memory situations on nodes, where the processes with the largest memory usage are killed by the kernel (by using OOM killer), yet no mechanism is available for prioritizing important processes that must not be initial candidates for the OOM killer. The GPFS mmfsd daemon uses a large amount of pinned memory in the page pool for caching data and metadata, and so the mmfsd process is a likely candidate for termination if memory must be freed up.

  3. What are the performance tuning suggestions?

    For an up-to-date list of tuning suggestions, see the IBM Storage Scale FAQ in IBM® Documentation.

    For Linux on Z, see Device Drivers, Features, and Commands, in the Linux on IBM Systems documentation.