The "mosctl block" command prevents new remote processes from migrating
to that workstation.
The "mosctl expel &" move out MOSIX guest processes. Note that an & is used after the expel command, since expelling processes may take some time and we don't want the user login process to hang. The processes are expelled while the user logs in.
This command allows remote processes to migrate to the workstation.
On a Debian system using GDM the appropriate file to add this command is /etc/gdm/PostSession/Default .
Note that when adding the mosctl commands to the GDM script you shouldn't
interfere with the correct work of gdb.