The autoSplitOnly balancer configuration is currently technically equivalent to balancing off. It is still present in order to avoid breaking balancer settings parsing.

Proposed solution 1:

• Write an upgrade procedure that changes the persisted autoSplitOnly value to off
• Get rid of the autoSplitOnly mode

Proposed solution 2:

• Get rid of the autoSplitOnly mode
• Ignore parsing errors: if an unknown mode is set, balancer mode is considered off. And a warning must be logged when an invalid mode is set.