Chapter 8. InfiniBand subnet manager

All InfiniBand networks must have a subnet manager running for the network to function. This is true even if two machines are connected directly with no switch involved.

It is possible to have more than one subnet manager. In that case, one acts as a master and another subnet manager acts as a slave that takes over in case the master subnet manager fails.

Red Hat Enterprise Linux provides OpenSM, an implementation of an InfiniBand subnet manager. However, the features of OpenSM are limited and there is no active upstream development. Typically, embedded subnet managers in InfiniBand switches provide more features and support up-to-date InfiniBand hardware. For further details, see Installing and configuring the OpenSM InfiniBand subnet manager.