Nondisruptive upgrade (NDU) processing is configurable and can use either PMM or IMM.
For back-end software component upgrades (that is MDM, SDS, SDR, LIA package updates), it is sometimes preferable to use IMM. This type of NDU operation is quick, and the entire system’s rolling upgrade can be finished in mere minutes. If there are no known or suspected issues with the nodes being upgraded, IMM is a safe and speedy choice.
For upgrade flows that includes other node maintenance activities – such as firmware or driver upgrades done by PowerFlex Manager on racks or appliances – we recommend using PMM. These operations have a higher probability of lasting longer and increasing risk.