San advisory based on latency

Abstract

Determining an optimal path through a storage area network from a specific initiator to a specific target includes determining a plurality of possible paths through the storage area network between the specific initiator and the specific target, examining a plurality of previously-determined latency values for each of the paths, the previously-determined latency values being set according to empirical observation of propagation through each of the paths, and choosing a specific one of the paths having a lowest latency value. The previously-determined latency values may be determined by sending a command from the specific initiator to the specific target. The command may avoid queuing any I/O operations at the specific target. The command may be a status request command or a vendor specific command. The source may be a host system and the target may be a storage system. The previously-determined latency may be measured using a PowerPath Management Appliance.