Storage area network methods and apparatus for automated file system extension

The invention provides an improved SAN of type having one or more host digital data processors, coupled to one or more storage devices. At least a selected one of the hosts includes a file system that effects access by the host to assigned storage devices. This can be, by way of non-limiting example, an AIX journal file system, a Veritas file system, a Unix file systems using Veritas volume manager or other host platform file system that oversees file and other data accesses between the host and those assigned devices. In response to a request by (or on behalf of) the selected host for extension of the file system, a manager (e.g., executing on a further digital data processor) assigns one of more further storage devices to that digital data processor. An agent associated with the first digital data processor that responds to the assignment by extending the file system to include the assigned storage device.