As an example of the implementation of a Unix-based approach we will consider
the system due to Mandelberg and Sunderam [#MandelbergPMIUN##1#]. This is
broadly typical of the way in which processes and migration are handled.
The aim of the work undertaken by Mandelberg and Sunderam was to investigate
the feasibility of supporting process migration on a network on independent Sun
workstations running Unix 4.2 BSD and NFS, without any special support from or
modifications to the kernel. There is a clear separation between policy and
mechanism. The mechanism by which processes are migrated is distributed between
cooperating software on source and destination nodes. However, the migration
policy is made by a single agent, external to the migration mechanism; this
allows changes in policy to be made easily and independently of already
executing processes.