This utility is an external way to find and cleanup files still resident on 
disks of pools, but which have been otherwise removed from PNFS. It is thus 
used to clean out pools in dCache, and can be used to trigger manual cleanups
of the PNFS namespace.

Optional Arguments:
	-quiet                        Run in quiet mode.
	-delete                       Perform actual delete.
	-pools <pool1>,<pool2>        Optional. Comma-separated list of pools
                                      to examine (default is all pools).
	-maxdelete <float>            Maximum percentage of files which can be
                                      marked for deletion before the script
                                      panics and turns off (must be between 0 and 1).
	-safefile <filename>          The name of a file which is known to exist.
                                      If this file doesn't exist, the script exits.
                                      This is to prevent cases when PNFS reports
                                      that *no* file exists due to DB problems.
        -badlist <filename>           Create a file <filename> with list of bad
                                      replicas, one pool and file per line
	-checktrash <trashdir>        Check whether the file is scheduled for
                                      deletion by examining the contents of the
                                      pnfs <trashdir>.