tcopy

[Nifty Hat Mitch]

On Tue, Sep 14, 2004 at 12:26:41PM -0500, Will McCorkle wrote:
> On 09/14/2004 01:52 PM, Will McCorkle wrote:
> > I have recently been given the dubious task of copying a bunch of 8mm 
> > exabyte tapes. I have gotten fc2 to recognize the Mammoth drives I  have 
> > installed, but there is no way I know of to do tape to tape copy. I 
> > found a copy of tcopy compiled for Linux, but it is 2 years old and 
> > doesn't seem to work. Any suggestions on an alternate software to copy
> 
> > tape to tape would be wonderful.
> 
> Do you have two tape drives?
> 
> Yes, both are Exabyte Mammath 8900 drives and I can pull and put data
> from both drives, but when I try tcopy it gives i/o errors.
> 

Tapes can be problematic.  
Make sure you know how to write protect them.

Exabyte tapes might take you into the strange tangled arcane world of
tapes.

It is important to know something about the way the tapes were
created.  System, application and drive can all play into the mix.

Do some serious web searching... this URL is a start
for some key words.

   http://www.mssl.ucl.ac.uk/www_computing/buns/tapes.html

Download the OEM manual for the 8900...

My memory is not 100% on this but the Exabyte family had a physical 4K
block size and with software mode commands would morph look like a host of
different formats.  Common UNIX tapes were a stream of 512 byte blocks
or single streaming large block writes (single 80MB DMA on 1/2" tape).
There is also variable block mode.  Then some twit tossed in compression....

The drive is controlled by the application via the driver with a
series of "mt" or "st" commands.  (See the man page for mt(1), st(4)
also look at sys/mtio.h).

You might have success with the variable block size devices.

If all you want to do is copy and replicate the tapes you might take
advantage of the physical layer design and do physical block copies
but I do not know if or where this Exabyte drive keeps it's meta
data.... to know if this is possible.

Do you still have access to the system and process that created the media.
If you can create some tests and verification cases you will be better off.

Also call Exabyte if the OEM manual is unclear.

I have had luck with remote tape devices....


-- 
	T o m  M i t c h e l l 
	In the USA, vote informed, second Tuesday Nov 2004.