Hey great suggestion! Unfortunately, when I tried it, I got the same thing.
RATS! For a second, I thought we had it licked!

simmons@dakkon[56]%  tar --block-compress -c -v -z . > ~/home.tape &
tar (child): can't write to /dev/rst0 : Input/output error
[1]    Broken pipe            tar --block-compress -cvz . > ~/home.tape

The dictory I was tar'ing was about 300MB. I tried a much smaller directory and
it worked. What does this mean?

Doesn't work across tape boundaries?

Gerry

---------  Received message begins Here  ---------

> From jfw@jfwhome.funhouse.com Sat Nov  8 08:48:49 1997
> To: "Gerald C. Simmons" <simmons@darykon.cet.com>
> cc: current-users@netbsd.org
> Subject: Re: AIC7XXX driver - No Tape support for writing 
> In-reply-to: Your message of "Sat, 08 Nov 1997 07:22:27 PST."
>              <199711081522.HAA04255@dakkon.darykon.cet.com> 
> Date: Sat, 08 Nov 1997 11:01:17 -0500
> From: "John F. Woods" <jfw@jfwhome.funhouse.com>
> 
> > Problem no. 1 Re-Addressed - Can't use "z" with Tapes?
> 
> > Nov  8 07:14:53 dakkon /netbsd: st0: bad request, must be multiple of 512
> 
> That is your tape drive talking there; it insists on fixed block sizes.
> (Most QIC tapes are like that, though the QIC-3080 and QIC-3095/TR4 tape
> formats actually can cope with variable length records.)
> 
> Read the tar manual page, and look for the "--block-compress" option.
>