🚀 go-pugleaf

Greetings,

  I'm trying to use GNU tar's W option to verify archives as they are created.
The manual says that this option will only work on a device that supports 
backspacing.  My Sun Cartridge tape and my Exabyte both support backspacing,
but I can't get the W option to work on anything other than plain files.  A 
small example output:

jupiter# ./tar cvWf /dev/nrst0 .
./
... <lots of files> ...
getdate.o
rtape_lib.o
rmt
./tar: read error on /dev/nrst0 : I/O error
./tar: read error on /dev/nrst0 : I/O error
... <message repeated about 10 more times> ...
./tar: Too many errors, quitting.
jupiter#

This happens with any tape drive that I try to use.  

One interesting thing about the Sun SCSI tape driver and tar:

   If I tar a file off the tape, and immediately execute a tar x on the same 
tape, then I get the same file the second time as the first time.  I think 
this is because tar doesn't actually read the past the file mark.  So, if you 
want to get the second file, you have to mt fsf 1 to get the tape past the file
mark.  Another aspect of this is that the backspace file operation (mt bsf 1)
will not work immediately following a tar (it dies with "I/O error").  You have
to fsf the tape past the file mark before the bsf function will work.  I don't
know if this is related to my problem or not, but I thought it curious.

This is all on a Sun4/280 running SunOS 4.0.3.  The Exabyte is using the same
driver as the cartridge tape, and so far none of the other programs we've 
used have had problems with it.

Thanks in advance for any info. 

Mark
cheeks@edsr.eds.com     or     ...uunet!edsr!cheeks