See existing documentation on the BUCS website and use the file recovery request forms at http://www.bath.ac.uk/bucs/help/contact/
Some file systems are being migrated to a more resilient and fault tolerant hardware. This in some cases means users can recover accidentally deleted or previous versions of files with no intervention for Computing Service staff. A list of file systems on which this is available will be added in due course.
For information on how to recover files on UNIX or Windows systems that support it see the documentation on Snapshot file recovery.