As someone who has been an end user and a system administrator,
I strongly believe that every user should understand the importance of
If you have data that is important to you, you should
have a known backup.
Accidents and oversights happen.
Tapes can be damaged, lost, or mislabeled.
Assume that your system administrator is top-notch.
The best administrator can recover your lost data 99 percent
of the time.
There is still a small chance that the files you need
might not be recovered.
Can you afford to duplicate months of effort 1 percent of the time?
An experienced user learns to be pessimistic.
Typically, this important fact is learned the hard way.
Perhaps a few hours are lost. Perhaps days. Sometimes months
Here are some common situations:
A user works on a file all day. At the end of the day, the file
is deleted by accident. The system manager cannot recover the file.
A day's work has been lost.
A programmer tries to clean up a project directory.
Instead of typing
the programmer types
rm * .o
and the entire directory is lost.
A user deletes a file by accident.
After a few days, the user asks the system administrator to recover
the file. The incremental backup system has re-used the
only tape the missing file was on.
A large project is archived on a magnetic tape and deleted
from the disk. A year later, some of the information is needed.
The tape has a bad block at the beginning. The system manager
must learn how to recover data from a bad tape. The attempt is often
unsuccessful. The information is lost forever, and must be
re-created, at the cost of months of effort.
Someone breaks into a computer and accesses confidential information.
A fire breaks out in the computer room. The disks and
of the backup tapes are lost.
I scared myself.
Excuse me for a few minutes while I load a tape...
Ah! I feel better now.
As I was saying, being pessimistic has its
Making a backup is easy.
Get a blank tape and put a label on it.
Learn how to load it onto the tape drive.
Then do the following:
tar c .
Take the tape off.
Write-protect the tape (slide the tab, turn the knob, or take out the ring).
Bruce also points out
that you can get even more protection by using a version control
to save every version of a file you are
updating frequently. -TOR