Processing input/output requests using proxy and owner storage systems

A proxy storage system, comprising:

• a proxy port coupled to a storage area network (SAN);
• and
• a processor configured:
• to receive an input/output (I/O) request from a host computer for a logical volume, the logical volume mapped between the host computer and the proxy storage system,
• to identify an owner port on an owner storage system for the I/O request, the owner storage system storing the logical volume,
• to convey, to the identified owner port, a probe request to verify an availability of the logical volume for the I/O request, and
• upon receiving, via the proxy port, a response from the owner storage system confirming the availability of the logical volume for the I/O request, to convey the I/O request to the identified owner port, to receive a result of the I/O request from the identified owner port, and to convey the result to the host computer.

An owner storage system, comprising:

• a storage device configured to store a logical volume;
• multiple ports configured to communicate with a proxy storage system via a storage area network (SAN);
• and
• a processor configured:
• to receive, via one of the ports, a probe request from the proxy storage system to verify an availability of the logical volume for an input/output (I/O) request from a host computer in communication with the proxy storage system, the logical volume being mapped between the host computer and the proxy storage system,
• to verify the availability of the logical volume for the I/O request, and
• subsequent to conveying a response to the proxy storage system confirming the availability of the logical volume for the I/O request, to receive the I/O request from the proxy storage system via the one of the ports, to process the I/O request, and to convey a result of the I/O request to the proxy storage system via the one of the ports.