Just to finish this matter.
This system now has been running ever since January 2005. I make a full backup every two weeks, alternatingly on two hard disks. Additionally, I make a incremental every day and write it to two alternating files on a third disk.
It is not a pefect back-up system, I can only restore from 1 or 2 days before, and then from 2 weeks or 4 weeks before.
In the mean time I have gotten a new tape streamer and use that one for weekly backups.
The system with the disks works very reliably and really is install-and-forget. For quite a number of times I have saved the day of one of our users after he had incidentally overwritten his file, or MS decided to write an empty file to disk instead of the full one.
Restore is easy, just enter the command to restore the file (which is a complicated command, but it still fits on one line
), forget, and some time later the file is back. It might take up to 2 hours for star to find the file from a 40 GB backup on a 1 GHz machine, that is the only drawback. The operation is very reliable however. My script writes a log file with all file names to disk, so it is easy to pick the correct file name. I use this more often than restore from tape.
Just wanted to let you know this, although it is trivial.