Computer system input/output management

The collection of performance data at multiple servers in a SAN and forwarding that data to a centralized server for analysis is disclosed. Remote agents and a central server application collect specific interesting negative event data to enable a picture of the operational health of the SAN to be determined. The agents are placed in servers having HBAs acting as initiators. The agents interact with the HBAs through a driver stack to collect event data. Because of the initiator function they perform, HBAs have visibility to parts of the network that other entities do not have access to, and thus are ideal locations for gathering event data. A SAN diagnostics manager then pulls the collected data from each agent so that a "picture" of the SAN can be developed. In addition to collecting initiator data, the agents also collect errors and performance data from the OS of the servers.