maximum job count has been reached

Hi,

I have a peculiar issue.

2 media servers : nodeA and nodeB
Each with 2 drives and mpx of 6 each, on 2 vtl's ( vtlA and vtlB.)

nodeA_vtlA 2 nodeA 8 6 6 2 0 "*NULL*" 1 6 1048576 *NULL* 0 1 0 0 0 0 *NULL* nodeA
nodeA_vtlB 2 nodeA 8 7 6 2 0 "*NULL*" 1 6 1048576 *NULL* 0 1 0 0 0 0 *NULL* nodeA

nodeb_vtlA 2 nodeB 8 6 6 2 0 "*NULL*" 1 6 1048576 *NULL* 0 1 0 0 0 0 *NULL* nodeB
nodeB_vtlB 2 nodeB 8 7 6 2 0 "*NULL*" 1 6 1048576 *NULL* 0 1 0 0 0 0 *NULL* nodeB

I created a storageunit group for each node with the 2vtl;s ie:

nodeA_vtl 3 nodeA_vtlA nodeA_vtlB

Added these 2 nodes to an app_cluster via nbemmcmd ( appA)

nbemmcmd -listhosts -list_servers_in_app_cluster -clustername appA
NBEMMCMD, Version:6.5.6
The following hosts were found:
media           nodeA
media           nodeB
Command completed successfully.
 

This app_cluster has a storage unit per VTL:

appA_vtlA 2 appA 8 6 6 2 0 "*NULL*" 1 6 1048576 *NULL* 0 1 0 0 0 0 *NULL* appA
appA_vtlB 2 appA 8 7 6 2 0 "*NULL*" 1 6 1048576 *NULL* 0 1 0 0 0 0 *NULL* appA
appA_VTL 3 appA_vtlA appA_vtlB
 

I configure a RMAn backup to use 6 channels, but with schedulr of mpx = 3.

I kick off a RMAN backup using the nodeA_vtlA srotage unit = all six streams go active and run concurrently.

I kick off a RMAN backup using the nodeA_vtl storage unit group = all six streams go active and run concurrently.

I kick off a RMAN backup using the appA_vtlA storage unit = all six streams go active and run concurrently.

I kick off a RMAN backup using the appA_VTL storage unit group = only 2 streams go active, and the other 4 remain queued.

I have deleted all the storage units, and app cluster, recreated them, and still only the app_cluster storage unit group only allows 2 of the six to go active.

The log details for the queue dbackups show:

Mar 26, 2013 3:31:10 PM - awaiting resource appA_VTL. Waiting for resources.
          Reason: Maximum job count has been reached for the storage unit, Media server: nodeA,
          Robot Type(Number): TLD(7), Media ID: N/A, Drive Name: N/A,
          Volume Pool: SAP, Storage Unit: appA_VTL, Drive Scan Host: N/A,
          Disk Pool: N/A, Disk Volume: N/A

Anyone come across similar issues and resolved them?

Many thanks,