Sun NFS aims to support heterogeneous distributed systems by the provision of an operating
system-independent file service. What are the key decisions that the implementer of an NFS server
for an operating system other than UNIX would have to take? What constraints should an
underlying filing system obey to be suitable for the implementation of NFS servers?

What will be an ideal response?

The Virtual file system interface provides an operating-system independent interface to UNIX and other file
systems. The implementor of an NFS server for a non-Unix operating system must decide on a representation
for file handles. The last 64 bits of a file handle must uniquely define a file within a file system. The Unix
representation is defined (as shown on page ??) but it is not defined for other operating systems. If the
operating system does not provide a means to identify files in less than 64 bits, then the server would have to
generate identifiers in response to lookup, create and mkdir operations and maintain a table of identifiers
against file names.
Any filing system that is used to support an NFS server must provide:
- efficient block-level access to files;
- file attributes must include write timestamps to maintain consistency of client caches;
- other attributes are desirable, such owner identity and access permission bits.