Video Screencast Help

Cannot unmount tape because library slot is already occupied

Created: 30 Oct 2009 • Updated: 21 May 2010 | 8 comments

Hi there,

I have got a strange phenomenon here. I see tape drives going down because the tape cannot be unmounted. This is because the source slot where the active cartridge originally came from has been occupied by another cartridge in the meantime.

I understand that this could happen if you would open the library and put new tapes into random free slots manually but that this should never happen if I use NetBackup to empty the CAP and do a robot inventory.

Could this be an inconsistency in the EMM database?

By the way if I do a robot inventory while the situation described above still persists NetBackup will tell me that the library contents is up to date and that no updates are necessary.

Any hint, no matter how small, is greatly appreciated.

Kind regards,

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thrahn's picture

Oh, I forgott about all the details. Shame on me.

- NetBackup 6.5.4
- Solaris 10 Master
- Windows 2k3 Media Servers
- Windows 2k3 Robot Control Host
- 2 x L700 Tape Library
- 2 x 4 IBM LTO2 Tape Drives

Tapes are being moved in and out of the library frequently.

If I move the tapes to free slots manually (via robtest) the tape paths will come up again and normal operation resumes.


Stumpr2's picture

First, I would get everything back to order and then I would closely monitor to see if it goes out of sync again.

I would stop all backups and return all tapes to their proper slot.
Then I would have the library do its inventory.
 I would follow that up with the netbackup media inventory.

VERITAS ain't it the truth?

thrahn's picture

> I would follow that up with the netbackup media inventory.

Stumpr, thanks for answering.

I'm not sure I fully understand what you mean by media inventory. The Media DB (yes, I know it's in the EMM :) ) does not have any information about library slots, does it? Well, I couldn't get any information about that by means of the "bpmedia" command anyway. Does the EMM have any information about library slots at all?

When I free the tapes and the drives come up again in NetBackup all is going well for a few days. I assume that things are messed up again after another bunch of cartridges has been replaced.


J.H Is gone's picture

Using the gui - look at the media screen - there is a column that will show you what robot and what slot in the robot the tape is in.

When the library does an inventory it knows where every thing is ( you see this if you open up the library door for some reason and when you close it, the arm scans all drives and all slots and all maps.) 

when you go to netbackup and do the inventory and say update it queries the L700 for what it knows and compares it to what NB has in the database and does a list of what needs changing - then asks you if you want to update.

you also state that you have 2 libraries  - when you do the inventory are you doing BOTH of them to make sure BOTH of them are up to date?

I don't have to know how to spell....I work on Unix.
NetBackup 7.0.1 - AIX & Windows

Stuart Green's picture

Make sure you have Removable Storage service stopped on any Windows Servers. This plays havoc with libraries and NetBackup they do not like to co-exist.

See all the technotes here:

Tip: Get overview/document your NBU environment. Run 'nbsu' and review the output.

• If this provides help, please vote or mark appropriate solution.

thrahn's picture

Hi Stuart,

I've turned off RSM on the new main media server but forgot to check with the existing media server in the DMZs. I turned off RSM after I first encountered the situation described above so I may still be seeing aftermath. I will double check on all media servers and do another inventory on all libraries.

I will keep you updated if the problem still persists.

Thanks for your help.


peterdcross's picture

For the third time (last Sat 31st Oct) this has happened to a customer I manage. NB6.3 etc. I originally thought it was the guys on site loading tapes “the easy way” but a check of the library logs showed the door of the library had not been opened. The recovery is simple via move in robtest, but the cause defeats me. Why cannot  tapes be loaded to any vacant slot and auto inventory take place? Netbackup is supposed to be an Enterprise Level product, the detection of a failure to unload because of an occupied slot should trigger and inventory and move tape. It’s not rocket science.

Zahid.Haseeb's picture

That thing happened with me as well. actually the Tape library should know that the busy tape which is in drive, went from the particular slot and the newly tape cant be imported to this slot. i think you should put the tape in to the drive before check the slot from the Netbackup Server 

Any comment will be appreciated. Mark as Solution if your query is resolved
Thanks in Advance
Zahid Haseeb