In the following section we discuss a range of different migration mechanisms
all of which rely on special features of either the operating system or
language in which they are embedded. Such features create a distributed
environment and make it relatively easy for two machines to cooperate in moving
a process from one machine to another. However, the UNIX environment was not
designed for distributed systems and lacks such features. This makes it
significantly more complex to implement process migration.
In this section we will consider the UNIX-based migration systems due to
Mandelberg [#MandelbergPMIUN##1#], Alonso [#AlonsoAPMIF##1#], Hunter
[#HunterPCASF##1#], and Freedman [#FreedmanEBAPM##1#]. Broadly, they appear
to impose similar restrictions on the processes which can be migrated. From
this it is not unreasonable to assume that such restrictions are fundamental
and inherent in the design of UNIX.