9 track storage capacity

[Roger W. Otterson]

I have recently been assigned the duty of backing up our system.
We have a 3b2/522 w/ (6) 322mb SCSI drives.  Needless to say it
takes some time to do complete system backups.

My backup device is a SCSI 9track tape drive.

My questions are:

How much can each tape hold (2400 or 3600 feet), and how do I
guesstimate how much tape I will need to backup a file system.
And what are the "magic" formulas to figure all of this out ??

Roger Otterson
Information Systems Group