The computer support staff never backs up the data on machines in offices. You are responsible for doing this yourself.
System accounts reside on the fileservers philologus and grad. Portions of each fileserver are copied to magnetic tape five days a week (in the middle of the night). The schedule is such that your account files are copied to tape at least twice a week. The tape rotation set comprises fifteen tapes. Thus, at any given moment, there should be six copies of your account files, spanning the last three weeks of changes. There are no backups going back further than three weeks. Furthermore, tapes sometimes fail, so of the six copies of your account, we may only get useful data out of a few of the copies (and those few might the oldest copies in the set). In short, if you ask us to restore a file from a backup, we may be able to comply, but the backup may be a few weeks old. Therefore, we highly recommend that you periodically make your own backups, especially after making a lot of important changes to your files.
To get a file restored, please contact the support staff immediately. Be sure to tell us the full path name of the file (i.e., tell us both the filename and which subdirectory or subdirectories of your account the file resided in), and also be sure to tell us the precise date and time the file was ruined or deleted. Please be aware that it takes two to four hours (per tape!) to restore files. The requested information helps us identify which tape is most likely to have what you seek. Because we may have to dig through multiple tapes, and because we may not be able to get to your request immediately, expect to wait up to a week to have your files restored. Please also be aware that we cannot guarantee the procedure to be successful. For this reason, we always recommend that you make your own backups, relying on us only as a last resort.
In the past, it was common to copy files to magnetic media, such as a floppy disk or a ZIP disk. Today, you will do better to burn your files onto a CD. They are inexpensive, are not susceptible to magnetic damage, and last a long time. (However, their exact shelf life is not well-understood, and seems to depend on the brand as well as the temperature and humidity where the CD is stored. Don't rely on more than a couple years! To learn more, try searching for "CDR shelf life" or "CDR lifetime" in Google.)
We have instructions on how to burn files to a CD in Linux.
At a minimum, keep a second copy of your files on your hard disk, and update
the copy whenever you make important changes to your files!
For example, on a Linux system, you can copy your local account
files to your /scratch partition using the following command:
cp -a /home/myaccountname /scratch/
This will protect you from your own mistakes (such as accidentally deleting a file), but will not protect you from a physical hard disk failure. Thus, periodically, be sure to make a backup onto removable media.
