Files on user filesystems are backed up to tape mainly so they can be restored in case of a disk failure, accidental deletion, or intentional deletion by a hacker. You should not rely on the backup system to recover your files after you intentionally delete them (although in most cases the backup system should be able to recover them), rather you should put your files on your own backup tape that you keep. Filesystems not listed in the user filesystems list are NOT backed up. The user filesystems are completely backed up to tape once a quarter, usually on the first of January, April, July, and October. Changes made after this full back up are backed up daily to a different set of tapes. The full (quarterly) backup tapes will be kept around permanently, but it is difficult to restore files from backup tapes older than 6 months. The incremental tapes are recycled after 3 months. This is one reason why you should not rely on the backup system to recover your files since if your files were created after the last full backup and you waited over a quarter to restore them they would no longer be stored on any backup tape. All files and directories on the user filesystems are backed up to tape EXCEPT for the following:
The incoming mail directory. Any file or directory in your directory tree named: mail, Mail, nsmail, mbox. I believe everyone keeps their email in one or more of these directories/files. Please only use these names to store your email in. This way we can honestly say that email is never recorded on backup tapes. Email is considered a State Public Record and therefore is subject to the State Public Records Act (RCW 42.17.250 et seq.) See UW-GS5 for more information. In particular, if requested by a member of the public, email must be transmitted to the UW Public Records Office for review and possible release. Tape or disk copies of deleted documents are also subject to the Public Records Act. By not backing up email to tape we do not ever have to be responsible for retrieving email files from tape. According to UW-GS5, email that is considered to have no administrative, legal, fiscal, or archival requirements for its retention may be deleted as soon as it has served its reference purpose. See UW-GS4 more information. Any email that does fall into the categories listed in UW-GS4 should be printed out and retained according to the University General Records Retention Schedule. Any file or directory in your directory tree named .netscape, or that begins with .newsrc. I believe everyone keeps their netscape browser related files and internet newsgroups in these files. Please only use these names. This way should a request for these files by a member of the public be received we can honestly say that these files are never recorded on backup tapes and we do not ever have to be responsible for retrieving them from tape. Any file or directory in your directory tree named core. The filename core is sometimes generated automatically by programs that terminate abnormally and contains a core dump which can be used to help debug the failed program. Typically however they are never used and can waste a lot of backup tape. Any file or directory in your directory tree named nobackup. If you have files that do not ever need to be backed up to tape, make directories named nobackup anywhere in your directory tree and put the files there. Note that should a disk failure, accidental deletion, etc. occur, files in your nobackup directories are lost forever. The ".nsr" file can be used in a directory to specify files or sub-directories to be skipped. See "man nsr" for details.
Now say if a disk failure occurs our email folders for example would be lost forever which we don't want. So everyday a copy of the following directories and files is generated and placed on a different disk drive (which is also never backed up to tape):
The incoming mail directory. Any file or directory in your directory tree named: mail, Mail, nsmail, mbox. Any file or directory in your directory tree named bookmarks.html or begins with preferences or begins with .newsrc. I believe the netscape bookmarks and preferences files which are typically kept in your ~/.netscape directory are the only files worth backing up, the remaining files in that directory like netscape's disk cache and history files are not important.
This other disk drive will only keep the last five days worth of copies so should you delete something in one of these directories you will only have four days to recover it before its lost forever. This policy went into effect in February 2000. If you have questions and/or suggestions about the backup policy please talk to Harry or David.
P.S. Thanks to Marc Michelsen for allowing me to use his policy and web page as a model for our policy and web page.