Play It Safe

The dynamic I/O commands are like any other z/VM® commands: temporary. They only remain in effect until the next power-on reset (POR) of the processor. If you make dynamic I/O changes without:

Making the same changes to the IOCP source file,
Generating and writing a new IOCDS file to the SE hard disk,
Making that IOCDS file the active file,

and someone performs a POR, you will lose all of your dynamic I/O changes.

How to Circumvent This Problem: Use the Lock-Step method while making dynamic I/O changes, not the Plug 'n' Play method.