if you want to access data on particular HD, you can S/FTP the data, but if you need the entire HD onto your box ( where you are currently logged ) yes, you need to NFSmount this partition.
Hostname is a reference to a machine unique name, e.g.
1 - mainframe.sysgate.org
2 - sysadmin.sysgate.org
These would be two different machines, each with CPU, Ram, etc, but still part of domain "sysgate.org"
Hope this helps.