IBM MetroMirror/Hyperswap configuration in MIA only environment

Products

• MIM Tape Sharing (MIA)
• MIM Resource Sharing (MIM)

Issue/Introduction

You are currently using a DASD MIM control file for handling tape drive allocations across multiple sysplex's. 
You are hearing there are issues with shared DASD volume in a Metro Mirror/Hyperswap setup.
You are interested to know what you may need to look at to continue sharing the MIM control files,  or whether you need to change the way you share tape drive resources.

Environment

• This is an MIA only environment. MII (GDIF) is not running.
• MIAplex consisting of systems in multiple sysplexes.
• Two separate volumes set aside for the Control Files.
  • volume1 has the CF00 control file.  (This DASD volume also has the MIM parms library)
  • volume2 has the CF01 control file.

Resolution

If in your Metro Mirror/HyperSwap setup, it will be required to convert reserves to global ENQ's, then here are some recommendations...

• If possible, exempt the 2 shared DASD volumes on which the MIA control files are allocated from HyperSwap. They don't need to be mirrored since there is no historical data that needs to be retained.
• Consider modifying the setup to utilize a virtual control file (VCF). This can be a considerable undertaking in a large environment.
• Split the MIAPLEX so that each MIAPLEX=SYSPLEX and have GRS convert the MIMGLOBL reserve for the MIA control files.

 Their may be an option to remove the need to convert hardware reserves to global enqueues. Check whether IBM APAR OA57049 is an option.