The goal here is to provide a job type with no execution at all, on any node ou frontend.
Indeed, using cosystem job type, oarexec is executed on the frontend typically. Hence if the frontend must be rebooted for a maintenance for instance, the job is killed.
This is a serious issue for long jobs.
Grid'5000 wants to use such jobs to manage long term reservation of storages.
Server prologue and epilogue must be executed however.