Using tar with apple 40 Meg Tapes

[Steve Green]

In article <1989Jul28.104713.5589 at gpu.utcs.utoronto.ca> owenr at gpu.utcs.UUCP (Russell Owen) writes:
>Hi,
>	I have a mac2x with AUX 1.1 on the internal drive and an apple 40 Meg
>tape drive.  I can format the tape with the mt command but don't seem to be
>able to tar files to the tape.  Is there some vital bit of knowledge I need?
>I have used tar on other machines successfully.  Is this not possible under
>AUX?
Well, the Apple Tape Bup requires 8k blocks and tar does not do that on default.
There are two ways to accomplish this.  First
	tcb < /dev/rmt/tc2 | tar cvf - {your files here}
works great assuming the stuff will fit on one tape and that you dont try to
append more files on to this tape afterwards.  It seems that the message to
swap tapes (assuming you have to) is sent to stdout and not stderr and it gets
sent to the tape. (Atleast I never see it)  The other method is much slower but
should work with all tar options.  
	tar cfvbB /dev/rmt/tc2 16 76700 {files}
				   ^^ this number is the number of blocks on the
tape and since all my tapes have slightly differant number of blocks, I use this
(safe) number.  That is, your mileage may vary.  (I have some old tapes)
--
						-steveg at tove.umd.edu
Disclaimer: I am not responsible.