Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!rutgers!elbereth.rutgers.edu!latzko
From: latzko@elbereth.rutgers.edu (Alex Latzko)
Newsgroups: comp.sys.att
Subject: Re: 9 track storage capacity
Message-ID: <Feb.3.13.16.13.1989.24019@elbereth.rutgers.edu>
Date: 3 Feb 89 18:16:13 GMT
References: <97@isg300.UUCP>
Distribution: usa
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 25

In article <97@isg300.UUCP> rwo0@isg300.UUCP (Roger W. Otterson) writes:

> 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
The normal rule of thumb is a 2400' 1600bpi tape will hold 40Mbytes
when blocked at 32Kbytes/block.  140Meg is the figure at 6250.

You can figure it out if you know the lenght of a block in bytes
and the number of blocks written in a group.  The distance between 
blocks on the tape is called the inter record gap and if memory
serves is 1/4 inches.

> Roger Otterson
> Information Systems Group
cheers
/S*
latzko@rutgers.edu
{backbone}!rutgers!latzko