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.