Production filesystems are subject to periodic purges (typically on the order of weeks or months) where data which has not been accessed recently is deleted. This means that it is possible for some restarts of very long-running simulations to be deleted by the system. This can be addressed by an automated archiving system, but such a system does not address the problem that the simulation metadata directory (currently called SIMFACTORY) and any restarts which have not been run yet, will also be purged. This would make it impossible to submit future restarts and limits the number of chained restarts you can submit to the purge time of the system.
One possibility to solve this problem would be to store a backup, or "shadow" copy of all the simulation metadata in a non-volatile location. This could be the user's home directory, or a "work" directory which is not purged. The details would need to be worked out.
This is not a serious issue yet.