Note that the pvmgetarch included with this distribution differentiates between SUN4Ms and SUN4Cs. Sometimes ckpt files are missing, sometimes the appl.ckpt file has missing or duplicate entries. As far as we know, migration and checkpointing work just fine in all other respects. No surprises there. Both commands have short entries in the console's help facility.
First lets go over ckpt.
The syntax is as follows. The console must be running on the machine from which tid is to be migrated. Attempting to migrate a task that is not currently running on the same host as the console will cause MIST to spit out an uninformative error message. So, that's a 30-second intro to ckpt, restart, and migrate. If aimk sees this it will exit with an error.