Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!bonnie.concordia.ca!antares.concordia.ca!goldfish
From: goldfish@concour.cs.concordia.ca (Paul Goldsmith)
Newsgroups: comp.unix.questions
Subject: Re: How can you verify DUMP tapes.?
Message-ID: <884@antares.Concordia.CA>
Date: 26 Mar 91 15:35:46 GMT
References: <1991Mar23.091409.1345@mdcbbs.com>
Sender: news@Antares.Concordia.CA
Organization: Concordia University, Montreal (Quebec)
Lines: 36
Nntp-Posting-Host: sunkisd.cs.concordia.ca

I have been using the following to verify my tapes:


	TAPE=/dev/yourtape

	(
	 while ... ; do
	   mt -f ${TAPE} stat
	   dd if=${TAPE} bs=... of=/dev/null
	 done
	) 2>&1

replace the "..." with the appropriate blocksizes and commands to sense the end of
tape.

This will display something like:

Exabyte EXB-8200 8mm tape drive:
   sense key(0x0)= no sense   residual= 0   retries= 1271
   file no= 19   block no= 0
0+32 records in
0+32 records out

where the info matches up with the output of the original dump.  (I use "dd" for my
dumps anyway as something like "dump ...f...  ... - ... | dd of=/dev/yourtape bs=...")

While this won't tell you that every byte was correctly written and recoverable,
it will tell you that the tape got the right bytecount, and that the data is readable.
My logic is that if I didn't trust the software to do its job, I would use other
software.  At least I know that the hardware didn't find any dropouts on the tape.


--
--	  Paul Goldsmith
<goldfish@concour.cs.concordia.ca>				 (514) 848-3031
	(Shirley Maclaine told me there would be LIFETIMES like this)