DLT VS80 gives write protect on old tapes

[Raoul Blommaert]

When I load tapes written by my old 20/40 GB Compaq DLT drive in my new HP DLT VS 80 drive they are flagged as write protect. I cannot write on them, nor erase, nor reformat those tapes.
There is no problem reading those old tapes.
I'm working on a NT4.0 SP5 server.
I use ArcServeIT WE v6.61 build 834 (newest).

[Vincent Farrugia]

Hello,

VS80 drives use the DLT1 technology, which are backward-compatible ONLY to the DLT4000 standard DLT drives. You previous drive is one of these, so that is why you can read these tapes successfully.

However, VS80 drives cannot write using the DLT4000 standard, so that is why you are getting a write-protected LED.

Are you using DLTtapeIV as your cartridges? These should be black. If you are using other tape cartidges (white or gray), these will not be written by a VS80. You need black cartidges (40/80Gb) for VS80.

HTH,
Vince

[Raoul Blommaert]

Vincent,

Yes, I'm using the 40/80 GB black tapes.

Kind regards

Raoul

[Vincent Farrugia]

Hello,

You need to reformat your cartridges, otherwise you won't be able to write anything on them.

Track density and bit density are different for the different technologies, even tape speed; it changes. I do not know how to do this on ArcServeIT, though. But that is what you need to do, definately, since you cannot write using DLT4000 technology using a VS80. You don't want to do that of course, seeing that you bought the VS80 to be able to store 80Gb compressed data instead of 40Gb...

HTH,
Vince

[David Ruska · Accepted solution]

> You need to reformat your cartridges, otherwise you won't be able to write anything on them.

It more than just a "reformat". The drive cannot reformat the tapes. They need to be degaussed with a VERY STRONG deguasser - something a lot stronger than what you would buy at radio shack. The one I've seen weighs about 100 lbs. There might be services available that can do this for you.

Thus, it's best to keep DLT-written media in DLT drives, and DLT1/VS80 written media in those drives.

[Frank_53]

Could this be the same problem I'm having? I have DLT IV tapes (40/80GB) currently used with an HP DLT 40 and NT Backup. I wanted to re-use these on a VS80, using Retrospect Software(Server 6.0). The unit only gives me "unrecognized format" when trying to erase these tapes. Any Ideas? Thanks for your help

[David Ruska]

Frank,

Yes, sounds like the same problem. You can read a DLT40 (aka DLT4000) tape in a VS80, but you cannot write (i.e. append) to it, nor can you reformat it.

You would need to have them degaussed as mentioned above.

[David Ruska]

Here's the answer I posted in a similar thread:

I think there's some misconception on reusing DLT-written media.

Here's the best answer I've seen:


Question: Why will DLT1 not overwrite DLT 4000 format media unless I degauss* the media?

*= degaussing is a process of "randomizing" the magnetic particles (or dipoles) that are embedded in the media formulation - effectively restoring the media to a "virgin" state. Degaussing is also sometimes called bulk erasing.

Answer: DLT 4000 format written by DLT 4000/7000/8000 drives "saturates" the media magnetically more than the thin film/MR head used in DLT1. It is possible that in the course of overwriting, some of the residual DLT 4000 format will interfere with the new DLT1 format, causing higher error rates or inability to read the new DLT1 format.

Erasing a tape is not the same as degaussing as the format itself will still be resident on the tape.

The power needed to degauss a piece of media depends on the "coercivity" of the media (DLTtape IV tape media is rated at 1850 Oersteds). The degaussing equipment needs to have a coercivity rating of three times this value to operate effectively. Many manufacturers of degaussing equipment do not specify their Oersted rating but rather the types of media they are capable of degaussing.

One source of degaussing devices or services can be found at:
http://www.audiolabelectronics.com

[Marino Meloni_1]

HI
the problem is similar to the onw it happens when floppy disk of 1.44 Mbyte appear on the market,the power of the magnetic field used by the "old" 720 Kbyte disk drives was higher and the head was larger, so the tracks recorded where larger, with new tecnology, we could read, but never clear these large tracks.
Here the process is similar, with lower and concentrated "magnetic power" it si not possible to remove previous largers tracks.

Bye

Marino