This article describes how to reboot nodes in a cluster non-disruptively without manual storage takeover/giveback using the Automated Non-Distruptive Upgrade (ANDU) feature.
Sometimes customers require to do fast non-disruptive reboots of nodes in a cluster which lies outside the scope of ONTAP upgrade. Typical use cases will include reboots after applying security patches or any other settings update which require the node to be rebooted. Manual takeover/giveback of each node is a time consuming process as the size of cluster grows. Moreover, manual takeover/giveback is a quite risky proposition and is subject to human error. Hence, ideally we would need a process that does everything that an Automated NDU process does sans the ONTAP image update.
As a way to tackle this, if the nodes are updated to the same image on which they are currently running on, we can perform a reboot of the nodes without having to do manual takeover/giveback. In this way, the nodes can be rebooted automatically for purposes which does not warrant an ONTAP upgrade. It has to be noted that, this procedure applies to clusters with 2 or more nodes.