Special Considerations for Modifying Node Role Assignments

By default, only one node is configured with the resource_management role. The resource_management role consists of one or more SLURM controller daemons and the LSF execution host. If only one node has the resource_management role, both SLURM and LSF controller daemons run on that node, and no fail over of these components is possible.

HP recommends that you configure at least two nodes with the resource_management role to distribute the work of these components and provide a failover configuration.

If you expect LSF to be accessible from outside the HP XC system, all nodes with the resource_management role must also be configured with the external role and have the appropriate hardware and wiring to directly access the external network.

You must assign the disk_io role to any node that is exporting SAN storage.

By default, no nodes are configured with the login role. Assigning a login role to a node enables the LVS director service. You must assign a login role to each node on which you expect users to be able to log in and use the system.

By default, no nodes are configured with the nis_server role. Assigning a nis_server role to a node establishes the node as a NIS slave server. Any node assigned with the nis_server role must also have an external network connection defined.

You must assign an external role to any node that has an external network connection configured.

By default, no nodes are assigned with the cisco_hsm or voltaire_hsm roles, which are required only if your InfiniBand hardware configuration does not contain a functioning subnet manager.

You can use a host based subnet manager from Cisco or Voltaire in certain InfiniBand switch configurations where there is no InfiniBand managed switch running a subnet manager. A functioning subnet manager is required for a functioning InfiniBand fabric.

A typical use for a host based subnet manager is for small server blade configurations that only contain blade InfiniBand switches, which are unmanaged. In this situation, using a host based subnet manager can eliminate the cost of an extra external switch, however, additional license costs for the host based subnet managers apply reducing the cost advantage.

Another instance where a host based subnet manager is required is in a hardware configuration with only large (> 24 port) Cisco InfiniBand switches that do not run subnet managers.

See Section  and Section  for more information about the cisco_hsm and voltaire_hsm roles.