In this project, Andrew Stewart and I have produced a modified version of tcsh that can migrate from machine to machine. A modified xterm has been developed that allows for the contents of the screen and the scrollback area to be saved and restored. When migration occurs, xterm and tcsh are started on the target machine. Screen and scrollback information is passed via a file.
Migration is triggered in one of two ways.
First, a new shell build-in command, smigrate , causes migration to the specified machine. Migration occurs automatically if the migration policy decides that substantially better performance can be achieved on some other machine. The migration mechanism works well, and I was used for a period of several months. The migration feature has proved to be very useful in moving from a machine that is about to shutdown, moving to a machine that has some special capabilities, and in moving to a less loaded machine. A simple migration policy has been implemented, but further work is required to assess its effectiveness.