Mainframe Enablers TimeFinder SnapVX and zDP 8.5 Product Guide

This feature lets you dynamically update the definition of an active VDG without a VDG restart.

If a VDG device definition is modified for an active VDG, a dynamic change flag is set for the VDG at the end of zDP Definition Utility (EIPINIT) processing. When the Dynamic VDG Update feature is enabled, zDP checks for a dynamic change at the end of each cycle. If the dynamic change flag is set, the local VDG control blocks are dynamically rebuilt before the start of the next cycle. In addition to device changes, any changes to VDG runtime options are also dynamic.

You can enable or disable the Dynamic VDG Update feature using the DYNAMIC_CHANGE parameter on the DEFINE VDG or MODIFY VDG OPTIONS command. Alternatively, you can select the Dynamic Change option in the Specify Versioned Data Group Parameters panel.

To view the status of the Dynamic VDG Update feature, issue the QUERY VDG STATUS command and look for the Dynamic_Change value:

...
EIP0021I     Terminate_Policy(OLDEST),Dynamic_Change(NO)
...

The status is also shown in the zDP VDG Configuration Information panel and in the zDP VDG Monitor report.