The department makes long-term backups of all the UNIX machines every six months. These tapes are kept for a period of five years. If you find you need a file from a long time ago that is not on the nightly backup tapes, we may be able to find it for you on the archive tapes. This is not foolproof, however. Anything that was created and deleted between archive runs will not be on the archive tapes, so they are most useful for static files that were sitting around for a long period of time. Fortunately, if it took you more than a month to miss it, it was probably old and dusty enough to get onto one of the archives.
The systems staff will automatically check the archive tapes if your files are older than the nightly backups. However, please be patient, because searching the archive tapes takes longer than searching the nightly tapes, since there are more of them and they are in storage, not readily available.