I wrote a python script (userapps/release/cds/common/scripts/delete_daq_empty_files.py) which will delete any zero sized gwf or md5 files in the current directory. It defaults to 'dry run' mode (lists files which would have been deleted).
I ran this on h1fw1's 11970 and 11969 directories for full, second and minute files to clean the file system up after Sunday's disk filling event.