Problem trying to READ a P2P tape in a DR system
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Problem trying to READ a P2P tape in a DR system

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Article ID: 191355

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Updated On:

Products

Vtape Virtual Tape System

Issue/Introduction

We have a P2P environment set up and all is fine with that.

The system is DR eligible. The customer wanted to access these P2P tapes to see if they are recoverable. Since this would not be a P2P environment, they set it up as a VTAPE classic environment.

The VTAPE instance comes up ok, the drives are online and the catalog looks good, however, the customer's batch job goes into device allocation looking for a tape drive.

Looking for some advice.

Environment

Release : 12.6

Component : CA VTAPE

Cause

The VTDRIVE definitions of the DR system which is attempting to read the 'remotely' created volumes does not define any remote drives via the 'OnlineRemote' / 'OfflineRemote' VTDRIVE parmlib parameters.  Also, this DR system is not configured as a 'P2P' system, but rather as if it is not using P2P.  

Resolution

To allow read access to P2P/Remote volumes on a DR system, the system will need to be configured as if it is a P2P system (even though there is no intent to create new virtual volume data to be transmitted to a remote system), and the VTDRIVE definitions of the DR system will need to include device definitions for the 'remote' drives, as Vtape uses these drives when it recognizes a 'remote' volume that is to be mounted (i.e., Vtape will NOT use the 'local' drive definitions to read a 'remote' volume, and if no remote addresses are defined and online, the job will hang waiting for allocation).  

Additional Information

An example of the symptoms of this problem: 
==================================

10.53.09 J0321072  IEF244I A058775I STEP010 - UNABLE TO ALLOCATE 1 UNIT(S)  129 
   129                     AT LEAST 1 OFFLINE UNIT(S) NEEDED.          
10.53.09 J0321072 *IEF877E A058775I NEEDS 1 UNIT(S)  130                        
   130             FOR STEP010 SYSUT1                                           
   130             FOR VOLUME AC4790                                            
   130             OFFLINE, NOT ACCESSIBLE                                      
   130             0900-09BF 09C8-09FF 0B00-0B9F 0BB0-0BFF   


An example of the VTDRIVE definitions causing this problem: 
===============================================

<VirtualDeviceList> initialized from member VT8DEVT      
  Device           CU Initial State                             
  ---------            --    ---------------                           
  0840                 1    ChpidDeviceList                           
  09C0-09C7      1    Offline                                   
  0840                 2    ChpidDeviceList    
  0840                 2    ChpidDeviceList                                                
  09C8-09CF      2    Offline        


An example of corrected VTDRIVE definitions allowing successful processing (also, the 'PeerToPeerOptions' and 'PeerToPeerRemotes' members will also need to be active): 
========================================================================================================================================

<VirtualDeviceList>        
  VirtualControlUnit=1     
   ChpidDeviceList=840     
   Offline=09C0-09C3       
   OfflineRemote=09C8-09CF 
  VirtualControlUnit=2     
   ChpidDeviceList=840     
   Offline=09C4-09C7       
   OfflineRemote=09D0-09D7