Incremental backups of the filesystem are made each night. These backups record any files which have changed since the previous incremental backup. If you delete something and then realise that you want it back, you can restore it yourself from the incremental backups by using the tkrestore command.
The tkrestore command is very useful and simple to use. To run tkrestore, simply type
% tkrestore &
If you are unsure of how to use it, there is a good explanation available by clicking on the help button in the tkrestore window.
Please note, any changes you made to a particular file on the day you restore it will not be salvaged, it will only be restored as the file it was backed up as on the previous night. Any files which are more than six months old will not be listed in tkrestore but will need to be extracted from full backups. You will need to contact System Support (email ss) in order to have this done.
More information about backups can be found at:
http://www.cse.unsw.edu.au/faq/questions/account-backups.htmlLoc Van Huynh 2007-03-15