The Universe attribute is specified in the submit description file. The PVM universe is for programs written to the Parallel Virtual Machine interface. The Globus universe allows users to submit Globus jobs through the Condor interface. In the standard universe, Condor provides checkpointing and remote system calls . These features make a job more reliable and allow it uniform access to resources from anywhere in the pool.
Condor checkpoints a job at regular intervals.
A checkpoint image is essentially a snapshot of the current state of a job. If a job must be migrated from one machine to another, Condor makes a checkpoint image, copies the image to the new machine, and restarts the job continuing the job from where it left off. If a machine should crash or fail while it is running a job, Condor can restart the job on a new machine using the most recent checkpoint image. Remote system calls make a job perceive that it is executing on its home machine, even though the job may execute on many different machines over its lifetime. You do not need to modify the program's source code, but you do need access to the unlinked object files.