Reusing Barcode labels 1

[sriranjani]

Hi,

I have a single policy, with retention period3 months.
Each DLT tape can hold data for a month. So, in the beginning of the next month, I am planning to use a new tape (but remove the barcode label from the previous tape and use for this new tape). Is this approach fine? Also, after using 4 tapes, I will start using the first tape again. How do I erase the contents on the first tape (even though the images are expired, I can see the contents and I am afraid that the contents will not be overwritten automatically).

Thanks in advance.

 

[comtec17]

Why do you have a retention period for 3 months if you are only holding the data for 1 month?

You cannot take a barcode off of a tape that is currently in the Database and not expired. NetBackup tracks tapes by the Barcode ID as well as header information on the tape.

Once a tape becomes expired, the data on it will be overwriten during the next backup.

To erase a tape depends on the OS that the master server is on. If you are using Solaris or AIX you can use the mt -f command like this "mt -f /dev/rmt/0cbn rewind" then "mt -f /dev/rmt/0cbn erase" then do a "mt -f /dev/rmt/0cbn rewind".

 

[sriranjani]

Thanks a lot 'comtec17'!. Your information is very useful.
'Each DLT tape can hold data for a month' - By this I meant that the backup data size is such that one tape can last for a month. But I don't want to expire the tape after one month. I need that data for 3 months.

Another question: If a tape expires (either automatically on the expiration date or manually by forcing it) can I use the tape with a different barcode? Will there be any problems writing new data with a different retention period? For e.g., old data's retention period is 3 months. And it is expired. The new data's retention period is 5 months. Without erasing the contents of the tape can I start writing the new data? I tried and it is giving me problems - even after I selected 'Allow multiple retentions per media'. Also, can I assign an expired tape to a different volume pool?

Thanks a lot once again.

 

[comtec17]

To answer your other question, yes, as long as the data on the volume is expired. To check if all images on the media is expired, run this command &quot;bpimmedia -mediaid <barcode> -L
Once you add the new barcode label on you will need to inventory the library and add the media to the &quot;scratch&quot; pool.
Once the media is inventoried, you may move the tape to any pool you would like. If you are getting errors while backing up to that media, I would do a &quot;vmquery -m <barcode> to see what the media is reporting.

If you are sure that all the information on that tape is expired, I would run the following command &quot;bpexpdate -ev <barcode> -d 0 -f&quot; and &quot;vmquery -deassignbyid <barcode> <pool> <status>&quot; and change the status.

 

[sriranjani]

Thank you. I have another question regarding this issue.
Say a tape is expired. I am sure that it is to be assigned to the same volume pool. So, I do not have to do vmquery -deassign and I don't have to move the tape to scratch pool, right? The next time I use the tape, the contents are going to be overwritten. Am I right?

 

[comtec17]

You are correct.