Examples perform input/output (I/O) requests, issued by a plurality of clients to an owner-node, in a virtual storage area network (vSAN) environment. I/O requests are guaranteed, as all I/O requests are performed during non-overlapping, exclusive sessions between one client at a time and the owner node. The owner node rejects requests for simultaneous sessions, and duplicate sessions are prevented by requiring that a client refresh its memory state after termination of a previous session.