Automatic startup of guest VMs _other_ than the CVM?


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I have a pre-production Nutanix block that I've been preparing for production use. My small datacenter experienced a failure in both street and UPS power a few nights ago, after which I discovered that guest VMs are set to manual restart by default in vCenter 5.5 when the host is powered up. I see the CVM on each node is set to automatically power on with the host afer a 30 second delay, which must be a Nutanix default.

So the question is, is it a good idea to power up guest VMs automatically with host power at all? If so, how long after the CVM is powered on should guest VMs wait to power up if they're set to auto start? Is the 120 seconds reasonable, or does the power up order imply that #1 must be fully operational before #2 is even allowed to start?

p.s., this question has really nothing to do with vCenter HA, best practices for which are documented reasonably well in the Nutanix lit. I'm not using VMWare HA, so my question isn't even this complicated.

5 replies

Userlevel 3
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The ESXi when booted accesses the NFS datastore from over the network while the local CVM is still booting up.How it works:In a Nutanix cluster, when you reboot one ESXi host, the datastore is made available to this ESXi host on bootup, this is achieved by putting in an route script on the ESXi (called autopath). The datastore is served through other CVMs running on other nodes in the cluster.So, you may configure autostart for the VMs to be booted up by default at a delay of 120s since they will be served through the network. Please be informed that if all the VMs boot up at the same time, the network bandwidth usage on the Nutanix cluster will be higher. This means VM bootup would be slower than usual.Once the local CVM is booted up completely and joins the Nutanix cluster, it can serve the NFS datastore to it's corresponding ESXi.On my lab cluster, it usually takes around 5-7 minutes for the ESXi to boot, the CVM to boot and become part of the Nutanix cluster.
Userlevel 7
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RDKB - Any particular reason you aren't using vSphere HA? Just curious.

But yes, it takes several minutes for both ESXi to boot, the CVM to boot, then the customer to come back online and stablize.

I'd say a good rule of thumb would be to add a ten minute delay, after the CVM's boot, to have auto start manager kick the VM's back on.

Not saying it will take anywhere near 10 minutes every time, but that will give the system a little bit to "cool down" and stablize everything, before you start booting up the rest of your workload.

If you end up thinking 10 minutes is to long, you could ratchet that value down to 7-8 and see how things settle.
Userlevel 7
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Hi @RDKB_IS

Did any of the responses provide you with help?


Hi, i just experienced the same but i'm running AHV 5.5

My VMs are Windows 2012 R2 std and one with Ubuntu 16.04

Is there a way to configure the VMs to start automatically after CVM and AHV booted up ?
Userlevel 4
Badge +14
Yes you can autostart them check this: https://www.cyberciti.biz/faq/rhel-centos-linux-kvm-virtualization-start-virtual-machine-guest/

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