Unable to resume suspended backup jobs

[Richard_Senda3]

Hello,

I am seeing a problem in NetBackup versions 7.0 thru 7.1 that I would like some assistance with.

The problem:
I "suspend" a running backup job by using the NetBackup Admin console or Java GUI.  Sometime later, I then "resume" this suspended job, again from the NetBackup Admin console or Java GUI.  When I resume certain suspended backup jobs, the following error is displayed in the Activity Monitor:

"Maximum job count has been reached for the storage unit"

and the job does not resume.

The problem is that the maximum job count has not been reached so the jobs should resume correctly.

Investigation:
From spending some time investigating this, I find that this error is only shown under the following circumstances:
The Storage Unit that is being used contains a single tape drive
AND
There are already other streams running to the storage unit when I try to resume the suspended job
AND
The job I am trying to resume is a multi-streamed job

Resuming a non-multi-streamed backup job works perfectly.

Steps to repeat the problem:
1. Configure a tape storage unit that contains a single tape drive.  In this tape storage unit, tick the box "Enable multiplexing" and set the "Maximum streams per drive:" to any number greater than 3.
 

3. Configure a backup policy that only contains a single stream:
On the Policy attributes tab, ensure that "Allow multiple data streams" is not ticked
On the schedules tab, create a schedule of type "Full Backup", set both the "override policy storage selection" and "Override policy volume pool" to the storage unit you created in step 1.  Also ensure that the "Media Multiplexing" box is set to 32.
On the Backup Selection tab, select something like "C:\" or ALL_LOCAL_DRIVES, it does not matter which
 

4. Configure a second backup policy that contains at least 2 streams:
On the Policy attributes tab, ensure that "Allow multiple data streams" is ticked
On the schedules tab, create a schedule of type "Full Backup", set both the "override policy storage selection" and "Override policy volume pool" to the storage unit you created in step 1.  Also ensure that the "Media Multiplexing" box is set to 32.
On the Backup Selection tab, make sure there are at least 2 streams, for example:
NEW_STREAM
C:\
NEW_STREAM
D:\
 

5.  Start both policies running.  Both should go "Active" in the Activity Monitor and start writing data to a single tape.  You should see at least 3 streams of data writing to the tape.

6. Suspend both policies.  When suspending the multi-streamed one, make sure you suspend the parent and not the children.

7. Resume the single streamed policy.  This should go "Active" and start writing data to the tape.

8. Resume the multi-streamed policy.  You will find that this will not go active, you will receive the error:

"Maximum job count has been reached for the storage unit"

9. You can confirm that the maximum job count has not been reached.  Suspend both policies again.  This time, resume them round the other way, so resume the multi-streamed policy first and then resume the single streamed one.  You will find both will resume and write data to the tape.

You can see that the stream limit has not been reached.  In each policy we set the multiplexing limit to 32 and on the storage unit, we set it to at least 3, so NetBackup should be able to write at least 3 streams onto the tape before showing this error.  This is explained in NetBackup 7.1 Windows Admin Guide vol 1 pages 572 to 579.

I see this behaviour in both the Windows and RHEL versions of NetBackup, versions 7 through to 7.1.  This behaviour did not occur in NetBackup 6.0 and 6.5 so it does look like a bug.  I have reported this to Symantec support some 8 months ago, but this has not been fixed, the case reference number is 412-338-721.

Has anyone else seen this problem?  Have you been able to fix it?

Thanks

Richard.