Rebooting a host: what does it do to running VMs

[PePierias]

Ok, this might seem a question that should not exist in the first place. But, let me explain.

ESXi caters for auto-starting VMs with specific delays. Which tells me that an ESXi host may start directly (ie without manually exiting some maintenance mode) VMs at startup.

Similarly, at least for reasons of cleanly shutting down due to power failure I was under the impression that if a host is ordered to shutdown, then it properly shutsdown (via VMWare tools) VMs and only then proceeds to shutdown.

Are my assumptions valid? I'm asking because I'm seeing more and more references to manually shutting down VMs and using (manually again) maintenance mode as an interim step...

Any advice will be appreciated.

[ashilkrishnan · Accepted solution]

Hi @PePierias ,

For graceful shutdown of VMs, you need to shut them down manually. vSphere does not perform a graceful shutdown of VMs when you shutdown ESXi directly.

Please refer the 'Note' here --> Reboot or Shut Down an ESXi Host 

More reboot-shutdown details here 

Hope that helps.

[PePierias]

There's something that I don't get though: if you have to manually shutdown VMs, what are the auto-startup and auto-shutdown options for in ESXi? These configurations options also include settings to cater for the delay between starting up one machine from the other, or shutting one machine after the last one did.

[depping]

mind you, the auto-startup up feature doesn't work when ESXi is part of a cluster, hence you see many folks talking about manually starting up VMs, as most folks will have a cluster of hosts vs a standalone host.

[PePierias]

@deppingthis is becoming more and more confusing (it's definitely inconsistent). At the moment I have the essentials license (therefore no HA). In this scenario, and coming back to my previous answer, what good is the startup/shutdown VM delays, if both startup and shutdown has to be performed manually and after/before exiting/entering the maintenance mode?

IOW, what's the purpose of the existence of these settings? From the looks of it, they should never be used per VMWare recommendations.

[depping]

If you have a single host, and the single host fails, then this feature would automatically power-on the VMs after the host is restored, that is where it would be useful.

[PePierias]

Thank you, that really helped me out here. I was certain that doing a host reboot (no HA) would simply shutdown VMs first. Obviously I was wrong.

Now what remains is to orchestrate a clean shutdown of the entire system of esxi hosts + NAS in case of power failure 🙂

Are things so complex even when dealing with vMotion/HA? That is, does one have to shut everything down, enter maintenance on all hosts, shut down hosts manually?

[alantz]

When you have a cluster and you put your host in maintenance mode VM's are migrated to other hosts. Then you can proceed with the shutdown/restart of the host safely. Newbie here, but that is what I do. 

--Alan--