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mismatch between media label and barcode

Created: 13 Oct 2012 • Updated: 14 Oct 2012 | 10 comments
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I have a media mismatch between my mediaa id label and media barcode.

 

Is it fine?

What is diffference between internal label and external label of a media?

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Andy2345's picture

 

When NB calls the tape for the first time the barcode is read and that same number is written to the tape as the Media id.  

or you could just bplabel the tape putting the media id on it without doing a backup.

Bplabel or when backup runs does the labelling by seeing what is the external media id obtained from inventory? and put that media id on the media header?

 

 

Marianne's picture

About the questions in your opening post:
My question to you:
Is this a real issue or another 'what if' question?
If it was real, you would know that it is NOT fine and you would have an error message to post here, right?

Questions in your second post were asked previously by NIKHIL in this forum. Please do a bit of a search - you will find the answer.

Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links

mph999's picture

This is not strictly correct ...

"When NB calls the tape for the first time the barcode is read and that same number is written to the tape as the Media id.  "

This is correct ...

"When NB calls the tape for the first time the barcode is read and that same number, or a slight varation of that numer as specified by the media id generation rule is written to the tape as the Media id.  "

You already posted the answer to your question, I have just changed it slightly to make it 100% correct.

Some 'homework' for you.

1) Why do we physically write a media id to the media header on a tape ?

2) Using the information below, what field am I talking about

My tape changer on my test server does NOT have a barcode reader, and my tapes do NOT have physical barcodes on them.  NBU works fine and I can tell what tape is in the drive by running the vmoprcmd command.  In the vmoprcmd command, one of the fields is blank.  If I look at the vmoprcmd command from my colleagues server (that has a barcode reader), this field is NOT blank.

M

 

Regards,  Martin
 
Setting Logs in NetBackup:
http://www.symantec.com/docs/TECH75805
 
Andy2345's picture

 

 

 

This is correct ...

"When NB calls the tape for the first time the barcode is read and that same number, or a slight varation of that numer as specified by the media id generation rule is written to the tape as the Media id.  "

 

Above is when we do inventory.

 

What bplabel does?It sets the internal media id obtained from media id generation rules of that media?

1) Why do we physically write a media id to the media header on a tape ?

So that NBU can recognize that tape.

mph999's picture

 

1)

"When NB calls the tape for the first time the barcode is read and that same number, or a slight varation of that numer as specified by the media id generation rule is written to the tape as the Media id.  "

 

Above is when we do inventory.

No - why would an inventory want to label tapes.

Think about the 'meaning' of the word 'Inventory' - forget NBU, "To check what is there and update records" would be an acceptable explanation of the word.

I presume you have at some point put tapes into a library, run an inventory and then run some backups to your new tapes.  What did you notice - hopefully that you did not personally have to run bplabel, or label from with the GUI, it just worked right ?

If you have not done this, you can accept my explanation above as being correct.

Therefore, what does this tell you about when NBU labels a tape ?

2)

What bplabel does?It sets the internal media id obtained from media id generation rules of that media?

More or less, yes.

3) Why do we physically write a media id to the media header on a tape ?

So that NBU can recognize that tape.

Yes, I would say that is an acceptable answer.  Really, a better answer would be to say that it uses the media id written to the tape to perform a physical inventory (vmphyinv command) which is an inventory carried out by reading the headers on the tapes, as opposed to barcodes.

BUT ...

The real reason it is written to the tape, is so that NBU can check that the correct tape has been loaded into the drive before it starts to write to it, relabel it, or in fact do anything with it.

There have been cases where certain companies (who I will NOT name) attempted to prevent legal investigations into their business by swapping barcode labels on backup tapes.  I DO NOT know if the software used was NBU or some other product.  Most if not all enterprise backup products write the media id (or whatever the term used by the other products) to the tape which prevents against this sort of thing.

 

Regards,  Martin
 
Setting Logs in NetBackup:
http://www.symantec.com/docs/TECH75805
 
Andy2345's picture

When NB calls the tape for the first time the barcode is read and that same number, or a slight varation of that numer as specified by the media id generation rule is written to the tape header as the Media id.  "

 

Is it correct?

mph999's picture

I posted that a short time ago, having editted the orignal quote to make it 'more correct'.

Do you actually think I would post something incorrect ?

 

Regards,  Martin
 
Setting Logs in NetBackup:
http://www.symantec.com/docs/TECH75805
 
Andy2345's picture

Finally

So bplabel sets the recorded media id of the tape which it fetches from the external media id obtained when we run the inventory?

mph999's picture

Almost

So bplabel sets the recorded media id of the tape which it fetches from the external media id obtained when we run the inventory?

There is no such thing as an external media id - a media id is 100% virtual.

This is correct.

So bplabel sets the recorded media id of the tape which it creates from the external barcode  obtained when we run the inventory?

 

Regards,  Martin
 
Setting Logs in NetBackup:
http://www.symantec.com/docs/TECH75805
 
SOLUTION
Marianne's picture

The topic of media id's has been beaten to death by NIKHIL, and now Andy2345 is resurrecting it...

Please read through all of these posts once more - it should answer your past, current and future media-related questions...

https://www-secure.symantec.com/connect/forums/what-use-media-id-netbackup

https://www-secure.symantec.com/connect/forums/barcode-rule

https://www-secure.symantec.com/connect/forums/media-id-mismatch-issue

https://www-secure.symantec.com/connect/forums/symantec-use-media-id-and-barcode

https://www-secure.symantec.com/connect/forums/media-mismatch

Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links