Definitions for teachers by teachers

Tape Backup

Our system administrator does biweekly back-ups, however this can vary from administrator to administrator.

For an example of a company that promotes tape backups' follow this link:

http://www.exabyte.com/

by Cynthia Clark

Tape Backup for servers on networks is an absolute necessity, although it’s always interesting to me to hear how many people don’t do backups.  When I was hired at my current job a tape backup had not been done in the 8 months prior to my arrival.

Tape backup in general is very reliable, assuming the backup drive and tapes are in good working condition.  It’s always good for administrators to check their tapes to make sure data is really being written on them.  I’ve heard horror stories of people backing up data up consistently for 2 years and having a catastrophic failure -- only to find out there is no data on their tapes (bad tapes or bad tape drive). 

The picture shown here is of a variety of tape backup hardware components.  The biggest one is a tape backup library.  Something like this would cost thousands of dollars but be intended for backup of a cluster of servers.   These units have autoloaders so you can load a whole set of tapes (like a week’s or months worth of backups) in one easy move.   The smallest component shown here is a single tape drive that is installed internally in a server or workstation (you load one tape per backup, and change that tape whenever needed).  These types of units run about $700 on a typical Wintel server.  They look just like a zip drive of floppy drive looks in your workstation when installed. 

On our servers at work we use DAT tapes and a software program called Arcserve, which manages the backups by scheduling them and by cataloging what is on each tape.  The tape logs let us know what was successfully backed up and what backups fail.  We even have notification at our desks every morning to let us know if the tape backup ran successfully or not.  Another popular server-based backup system for Wintel servers is BackupExec.

In general you have to rebuild servers (or workstations) after a catastrophe -- so you're just using your backup tapes to restore data files, not operating systems.  Once all of the appropriate software is re-loaded you restore your data files off tape.  There are backup software systems designed for autorecovery that restore the entire system, system software and all (most of these use your existing backup systems such as tape backup).  But these are very specialized and in general used for servers, not workstations.  Workstations can also be backed-up to a tape drive on a server by connections made over the local area network, and this is configured through the backup software.

by Amy Fahey

Some type of technical failure is inevitable resulting in a system crash.  It is likely your system will eventually go down.  In the process, you could lose the data your users store on your systems.  You can protect yourself by backing up your critical data.  Offline backup strategies are most commonly used.  It involves copying data onto small removable media often using compression techniques.  The most commonly used offline media is magnetic tape. Tape Backup is fairly inexpensive and simple to utilize but tends to be fairly slow.  Magnetic tape can be unreliable and requires careful handling and storage. It is still used often because the benefits outweigh the risk of losing important information.

Relevance:  It is crucial to have a tape backup of any important data. If your server or computer crashes, more than likely you will lose all of your data.  A tape backup of all critical data will ensure the ability to restore lost data.

by Jennifer Haberkorn

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