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Anuj Dhawan · Posted: Wed Sep 30, 2009 2:03 am Post subject: Delete a Tape

Hi,

I'm usually confused with this concept and I'd like to put my question this way...

"I need to delete a tape?" -- does the question in double-quotes makes a snese? By terminology, a tape-file (a file on a tape) can not be deleted, right? Then why do we have such threads every now and then...?

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Regards,
Anuj

Bill Dennis · Posted: Wed Sep 30, 2009 8:23 am Post subject:

You are correct that for physical tape there is no "delete" function. Until the tape is rewritten the data exists on the volume.

The person may have wanted to:

1. remove it from the catalog (and just used the wrong word)
2. expire the volume in the tape mgmt system for re-use
3. erase the data using a utility or magnetic degausser

Some tape mgmt systems do have a DELETE function to mark a volume as inactive.

Some virtual tape systems will delete the data on a virtual volume prior to the volume being rewritten.

Hope this helps.
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Regards,
Bill Dennis

Disclaimer: My comments on this foorum are my own and do not represent the opinions or suggestions of any other person or business entity.

Anuj Dhawan · Posted: Wed Sep 30, 2009 1:22 pm Post subject:

Thanks Bill. I was little unsure if I'm missing something as I said earlier,why do we have such threads every now and then and in multiple forums.

Sigh of relief, Appreciate your help... Smile

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Regards,
Anuj

Terry_Heinze · Posted: Wed Sep 30, 2009 6:25 pm Post subject:

I'm guessing that situation #1 is the most common.
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....Terry

Anuj Dhawan · Posted: Wed Sep 30, 2009 11:14 pm Post subject:

I'll go with what has written in parenthesis... Very Happy

..and this is not a language barrier, I believe - just sheer ignorance.
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Regards,
Anuj

expat · Posted: Thu Oct 01, 2009 1:03 am Post subject:

Yes, you can "DELETE" a tape by over writing it. I recall working for a bank and when a tape was scrapped, it was written over several times with generated binary patterns before being sent away for destruction.

In the event of faulty tapes, these were physically destroyed on site.
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If it's true that we are here to help others,
then what exactly are the others here for ?

Anuj Dhawan · Posted: Thu Oct 01, 2009 5:03 am Post subject:

nevilh · Beginner Joined: 11 Aug 2004 Posts: 115 Topics: 0

Anuj Dhawan · Posted: Thu Oct 01, 2009 6:39 am Post subject:

You make me scratch my head. I was thinking about DASD similar to "HD" of Personal Computers and TAPE as "reel castles" which we used to use in "music tape recorders" in old days?...mmm, I'm curious what actually happens at physical level Confused

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Regards,
Anuj

nevilh · Beginner Joined: 11 Aug 2004 Posts: 115 Topics: 0

Physically nothing happens. Only the pointers to the data are removed. If you want to test allocate a dataset using ABSTR . Add some easily recognisable data into the dataset. Delete the dataset . Reallocate the dataset using ABSTR . You should then be able to see the data that you added before deleting and reallocating the dataset . If you have no possibility to allocate the dataset without a close being performed, then after Reallocating the dataset use the DFDSS print command and you will see the data.