CA MIA - Adding a new device range of IBM TS7760 virtual tape drives - PATH NOT OPERATIONAL

Products

• MIM Resource Sharing (MIM)
• MIM Data Sharing (MII)
• MIM Tape Sharing (MIA)
• MIM Message Sharing (MIC)

Issue/Introduction

Adding new tape drives (TS7760) , it can happen that they don't go online and the D M=DEV  command shows the following message:

PATH OPERATIONAL N N 

Can CA MIA stop tape drives from coming online with the above message?  
 

Environment

Z/OS - CA MIA 

Resolution

If the  D M=DEV  command shows the following message:

PATH OPERATIONAL N N 

and the command VARY ONLINE - 
gets the following result: 

IEE103I UNIT nnnn NOT BROUGHT ONLINE 
... 
IOS551I NO PATHS PHYSICALLY AVAILABLE 

This is an IBM message indicating the path is offline to the tape device. Doesn’t looks like the device is set up correctly from a hardware point of view. 
CA MIA will manage vary commands at the device level, but bringing paths online to the device needs to be done via the operating system. 
The IEE message received when attempting to vary the device states that there are no physical paths. 
It is necessary to vary a path online to the device, before the device itself can be varied online and this is done at Operating System level . 

In some case it has been found that  there was a switch port blocking matrix in place causing this problem.