Home > Storage > PowerFlex > White Papers > Dell PowerFlex: Maintenance Modes > Mixing maintenance methodologies
Protected Maintenance Mode and Instant Maintenance Mode cannot occur simultaneously within the same Protection Domain. There are, however, no cross-protection-domain concerns when maintaining nodes, so IMM can be used in one Protection Domain while PMM is used in another.
If you are adding a node to a cluster or removing a node from a cluster, you can simultaneously initiate PMM on another node in the same Protection Domain.