DLT tape question

Richard_Goodwin@Dell.com Richard_Goodwin at Dell.com
Wed Mar 27 10:58:00 CST 2002


Jacob's explanation is correct, here is a slight variation of the answer:

The DLT1 can only read from a 4k tape. The DLT1 and 4K have different head
technologies. The signal that the 4K writes with is stronger than that of
the DLT1 therefore it can not overcome the signal strength to over write it.
Because they write in the same format the DLT1 can read from it. The reason
the DLT1 cannot read a 7K tape is because the head on the 7K writes at an
angle and the DLT1 head is stationary.  

One other thing the F/W in the DLT1 is supposed to detect the different tape
and flag the write protect bit. The orange light on the drive will also
light up when the dlt4k tape is inserted, regardless of the position of the
write protect switch.

Richard Goodwin - richard_goodwin at dell.com
Tape Hardware and Software Development



-----Original Message-----
From: JACOB_LIBERMAN at dell.com [mailto:JACOB_LIBERMAN at dell.com] 
Sent: Wednesday, March 27, 2002 10:50 AM
To: basil.hussain at kodakweddings.com; linux-poweredge at exchange.dell.com
Subject: RE: DLT tape question

here is the answer:

Type IV tape previously formatted/written by a DLT 4000/7000/8000 cannot be
used in a DLT1 unit. The ONLY way to reuse the tape is by degaussing or bulk
erasing the tape with special equipment then format the tape with a DLT1
drive.

The current DLT drives from Quantum uses a "Ferrite Head", which writes
"deeper" into the media than the Thin-Film MR (Magneto Resistive) head that
the DLT1 drive uses. So if the DLT1 drive attempted to write on a previously
recorded DLT4000 piece of media there could be residual magnetic properties
left deep in the media that could confuse the DLT1.

Richard Goodwin might know more about this issue.

cheers,

jacob

-----Original Message-----
From: Basil Hussain [mailto:basil.hussain at kodakweddings.com]
Sent: Wednesday, March 27, 2002 10:47 AM
To: Dell Poweredge Linux List
Subject: RE: DLT tape question


Hi,

> Note the WR_PROT status, i.e. write protected. Needless to say the
> physical write protect tab on the tape is off.
>
> Although tar on linux will happily read the tape's contents, there
> seems to be no way to write to the same tape.

[snip]

> So the $64k question - how do I get to re-use these tapes?

We have an HP DLT1e tape drive here, and the docs state that it will only
*read* DLT4000-written tapes. All the DLT1 tape drives I've ever come across
are the same. For the HP, with regard to writing to them, the manual states
that you may only do this when "a DLTtape IV has been bulk erased or
degaussed".

So, it would seem you can't re-use them as-is.

Regards,

Basil Hussain
---------------------------------------
Internet Developer, Kodak Weddings
E-Mail: basil.hussain at kodakweddings.com


_______________________________________________
Linux-PowerEdge mailing list
Linux-PowerEdge at dell.com
http://lists.us.dell.com/mailman/listinfo/linux-poweredge
Please read the FAQ at http://lists.us.dell.com/faq or search the list
archives at http://lists.us.dell.com/htdig/

_______________________________________________
Linux-PowerEdge mailing list
Linux-PowerEdge at dell.com
http://lists.us.dell.com/mailman/listinfo/linux-poweredge
Please read the FAQ at http://lists.us.dell.com/faq or search the list
archives at http://lists.us.dell.com/htdig/




More information about the Linux-PowerEdge mailing list