Make rerun directories writeable on the Hilo PFS cluster

Can we sort out permissions on /data/drp/repo/rerun?  I can't write to it, as we mounted the entire file system R/O (which is reasonable).  I think we need to replace that rerun directory with a symbolic link on both the summit and in Hilo, and make the Hilo one point to a writeable file system (e.g. /work/rerun).

The issue is that running the pipelines with a -rerun a/b/c option is extremely useful, and this expands to the directory /data/drp/repo/rerun/a/b/c so the user code needs to be able to write to /data/drp/repo/rerun. I don't think that it need be the same directory as on the summit (although that would be nice), so probably the easiest solution is to make it a symbolic link in both places, pointing to local disk.