Currently the sos task execution system is complicated because it needs to copy files around if files reside on directories that are not shared by the job submission machine and the head node. A lot of work, such as signature checking, directory mapping, and file synchronization has been done to enable a powerful, yet complicated and confusing system that can easily break.

I propose that we remove all the file mapping feature and require file systems to be shared. In this way input and output files have to exist on both local and remote file systems, and there is no need to map directories and copy files around. The system will be much easier to understand, configure, and a lot more robust.