A method and apparatus for providing multi-path I/O in non-concurrent clustering
environment is disclosed. Shared non-concurrent access to logical volumes through
multiple paths is provided by using SCSI-3 persistent reserve commands. Open options
of the operating system are mapped to SCSI persistent reserve commands to allow
all of the multiple paths to register with the logical unit number of the shared
storage system and to allow the second of the multiple paths to access the logical
unit number of the shared storage system after obtaining a persistent reservation
with the shared storage system.