Hello, the module will restart, not the chassis. But it is advisable to have downtime when doing any firmware updates.
v2.20 Only recently getting cmc redundancy loss alerts.  Lately also getting: SWC8619 CMC unable to process data for the server in slot 1. CMC8527 Unable to retrieve the server 1 memory information CMC8607 Unable to retrieve information about the firmware on server in slot1...... Need to update the CMC firmware first?  Both active and standby have the same v2.20 f/w. I have the update instructions. This is a running system; can I update the firmware while live without server interruptions?  Do I update one CMC then the other?  The instructions say to do both at the same time.  Does it matter which one is updated first on a live system? Any other suggestions? Thanks and sorry for the newby questions.  
VRTX CMC update