DEFRAG with a Primary and Shadow MUF

Document ID : KB000107007
Last Modified Date : 24/07/2018
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Question:
Can DEFRAG be run with a Primary and Shadow MUF?
CA Datacom Core - 15.1 section on “DEFRAG (Defragment Index)”
https://docops.ca.com/ca-datacom/15-1/en/reference/dbutlty-reference/utility-function-summary/defrag-defragment-index 
says “Cannot be run in a MUFplex environment if two or more MUFs are enabled
Is this restriction true for a Primary and Shadow setup?
Environment:
z/OS
Answer:
There is no concern running a DEFRAG to a primary MUF that has a Shadow MUF in waiting 

Given startup option: MUFPLEX plexname,*,,250,

The MUFPLEX mode 'S' confirms that no structure CF coupling facility is being used.

As per documentation on MUFPLEX and mode S: 
"To run in a Shadow MUF environment, specify an S as the mode for the MUFPLEX MUF startup option. For each physical MUF involved in the Shadow MUF environment, you should specify S for the MUFplex mode. A MUFPLEX mode of S is like a MUFPLEX mode of B in that no pipeline writes are done to the Coupling Facility. Implementation of mode S has only a small effect on how MUFPLEX modes A and B execute. For more information about running in a Shadow MUF environment, see Shadow MUF Environment. 
https://docops.ca.com/ca-datacom/15-1/en/administrating/ca-datacom-db-database-and-system-administration/using-the-multi-user-facility/modifying-muf-startup-options/mufplex "


The concern would be if a true multi-MUF environment was set up and using a CF structure with a different mode. 

DBUTLTY DEFRAG can be run from any lpar that has access to the active MUF via XCF. 

Example:
Primary running on LparA and Shadow waiting on LparB. 
Batch DBUTLTY with... 
/*JOBPARM SYSAFF=* 
... and ...
//SYSIN DD * 
DEFRAG DBID=dbid 
/* 

As long as the MUF is active (ENABLED) on either lpar, the DBUTLTY job will run via XCF from the submitted lpar (/*JOBPARM SYSAFF=*).
 
Additional Information:
Refer to CA Datacom Core - 15.1
Section on “DEFRAG (Defragment Index)”
https://docops.ca.com/ca-datacom/15-1/en/reference/dbutlty-reference/utility-function-summary/defrag-defragment-index
Section on MUF startup option “MUFPLEX”
https://docops.ca.com/ca-datacom/15-1/en/administrating/ca-datacom-db-database-and-system-administration/using-the-multi-user-facility/modifying-muf-startup-options/mufplex