In a post on the vSphere blog, I spoke about how to use maintenance mode. As a follow on request, a number of people asked me how they should safely shutdown a VSAN cluster. In this post, I will address that question and share my observations.
On my three-node VSAN cluster, I had a number of virtual machines as well as a vApp running vCenter Operations Manager VMs. My first step was to shut down all virtual machines in my cluster.
Once the virtual machines were powered down, I then proceeded to place my ESXi hosts into maintenance mode. When the maintenance mode wizard appeared, I made the following choices:
I unchecked the flag which specifies ‘Move powered-off and suspended virtual machines to other hosts in the cluster‘. The reason for this was because I was going to put all hosts into maintenance mode to shut down the cluster. Therefore there was no reason to migrate the virtual machines between hosts. I also elected to do no data migration for the exact same reason; there is no point in moving the virtual machine storage objects to other hosts/disks as I am shutting down the whole cluster. I put all three nodes into maintenance mode successfully.
With all virtual machines powered down, and all three ESXi hosts in maintenance mode, I then proceeded to reboot all three ESXi nodes. All hosts rebooted successfully, and of course, the VSAN cluster status was reporting issues with the configuration during this time as one might expect (no eligible disks and network issues):
Once the hosts rebooted, they reformed the cluster. I took each of them out of maintenance mode, and I was able to successfully restart all my virtual machines, including the vCOps VMs in the vApp. Note that at no point did I need to disable Virtual SAN on the cluster.
To recap, if shutting down the whole of the VSAN cluster, use maintenance mode for the hosts, and do not move VMs or migrate any data.