Most networks are always running short of file storage space on their live server(s). If you keep permanent periodic backups (i.e. monthly), this tip will allow you to delete large subdirectories of occasionally used files with a link directing you to the exact tape to load for performing a restore.
After completing a successful backup, delete all of the files in the subdirectory and replace them with a short text file using the date or ID of the backup tape you need to use to perform a restore. Most backup systems such as Veritas or ArcServe allow you to search through a database to locate the correct file and backup tape to perform a restore; this technique will allow you to locate the subdirectory where the files you needed were originally stored, and when you find them all missing---you will have a single file indicating the backup tape you need to use to perform the restore; or the date the files were deleted.