NetApp Element software 12.2 and above
When you need to take a storage node offline for maintenance you can minimize the I/O impact to the rest of the storage cluster by enabling maintenance mode for that node. Maintenance scenarios include any task that requires the node to be powered off or restarted. Maintenance mode does not need to be manually set for upgrades through the HCC (Hyper Cloud Control).
Note: Ensure that you perform maintenance on the node as soon as maintenance mode is enabled. Do not leave the node in maintenance mode any longer than necessary.