Some things to verify when merging Tape Grids.
VM:Tape 2.0 interfacing with RMS.
Update the DGTVCNTL DATA file in the VMSYS:DFSMS.CONTROL directory to specify the new library serial number on the RM_AUTO_LIBRARY statement.
Also, if you changed/added tape drive addresses they must also be made in the RMCONFIG DATA file in the same directory.
You will also need to recycle RMSMASTR after you make the change.
When updating the RMSMASTER configuration files with the new GRID information, after you restart RMSMASTER, you also need to restart VMTAPE to synchronize the updates with the RMSMASTR server.
Also verify that the RMSMASTR Server's directory entry contains this statement:
STDEVOPT LIBRARY CTL
Only the RMSMASTR Server directory entry needs this statement, the VMTAPE Server directory entry does NOT need the statement.
If this z/VM system is running in a z/VM 2nd level guest, the directory entry for this z/VM system must also have ... STDEVOPT LIBRARY CTL ... statement.