Deleting unwanted backup images from an active tape.

[PNabski1]

Good Morning,

We have large amounts of unwanted backup images on tape that a customer has informed us we no longer need to keep.

On an "Active" tape in the library is it is possible to delete the unwanted images. If so would Netbackup then be able to write to the space previously occupied any deleted unwanted image/s.

Kindest Regards

Peter Nabialek

[Nicolai · Accepted solution]

Hi @PNabski1 

You can delete the images on the tape (and Netbackup catalog) using the bpexpdate command, but Netbackup is not able to use the released space. All images on a tape has to be deleted/expired before Netbackup will re-use the tape.

Please see this blog on how Netbackup writes to tape.

https://vox.veritas.com/t5/Enterprise-Data-Services/Understanding-how-NetBackup-writes-to-a-tape/ba-...

[PNabski1]

Hi Nicolai,

Many thanks for the prompt answer it is very much appreciated. I suspected this might be the case but confirmation from an experienced  Netbackup person seals the deal. Big big thanks.

Kind Regards

Pete  ( a Netbackup novice )

[davidmoline]

Hi @PNabski1 

Adding to @Nicolai's answer - the images on tape will not be deleted until the tape is next overwritten. The bpexpdate command will remove the backup image information from the NetBackup catalog, but will not touch the tape (directly)

This means that while the tape is still active it will be possible to recover the backup information from tape by performing and import (this may be important to your customer if they are expecting the bpexpdate command to completely remove the data so that it is irrecoverable). 

David

[PNabski1]

Hi David,

Many thanks for the additional information. This is giving me a better understanding of the workings of backups to tape. This whole issue has come about due to a lack of communication between various groups of people inside and outside my company. It has become a priority topic as the server that backups were not required on is 9 TB in size and on LT05 tapes that equates to a fair number of tapes on the weekly full backups. Currently in the library I have managed to reclaim a number of full tapes with only this servers data on via "bpexpdate -m xxxxxxxx -d 0"  however this command does not work on a couple of "Active" tapes. I get messages more or less related to the safe keeping of the secured data which is understandable. I am now trying to search on how to reclaim these "Active" tapes for scratch.

Kindest Regards

Pete

[davidmoline · Accepted solution]

Hi @PNabski1 

If you want to determine what backups are on a tape you can do this a number of ways. 

Through the GUI in the catalog section is one way, although myself I prefer to use the command line.

To read the actual tape the "bpmedialist -mcontents -m XXXXXX" command will display all the backup images on a tape. You can then use this to expire those images to "empty" the tape ("bpexpdate -d 0 -force -backupid <BackupID>"). 

An alternate that just looks at the catalog is the "bpimmedia -mediaid XXXXXX" command which should provide the same information.

Once you have expired all the images from tape, the tape should in a short time become unassigned, but you can quicken this process by using the command "bpexpdate -deassignempty -m XXXXXX".

Now if you have multiple copies of backups or SLP's in use, then things can be more complicated (if multiple copies you may need to specify the copy number to avoid deleting a different copy of the backup). 

Have fun
David

[PNabski1]

Hi David,

Thanks so much for even more helpful information. I'll give it all a good work through shortly once I have done with my routine monitoring chores.

Kindest Regards

Pete

[Nicolai]

Hi @PNabski1 

If a tape is in the frozen state, and you run the bpexpdate command, Netbackup won't expire the images before the tape is unfrozen state.

bpmedia -unfrezze -m (BAR code label)  is memory serves me right.

[PNabski1 · Accepted solution]

Hi Nicolai,

Thanks for that info , made a note of it in case I come across the situation.

Kindest Regards

Pete