Saturday, 6 August 2016

In-Place Hypervisor Conversion from ESXi to AHV

It has been nearly 3 years since we bought our first Nutanix block. The NX-1465 was used in a ROBO location to provide some backup services for the main datacentre at the head office. Due to infrastructure changes this block started to see less and less use and a fine piece of equipment such as this is wasted when only hosting a handful of VM. Having found an alternative solution for these VM, I decided to convert this cluster to Acropolis Hypervisor. It will allow me to come to grips with a different hypervisor and also give us the ability to test some of the AOS features such as File Services and Containers.

Rather than destroying cluster and rebuild I wanted to see how good the conversion utility worked. Looking at the documentation it became clear that it is not a matter of just pressing the button, there are a few requirements to adhere to. Since the ESXi cluster was attached to a distributed switch I had some cleaning up to do. vDS is not supported so I migrated all physical adapters and vmk interfaces to a freshly created standard switch. Only one external vSS is supported btw. I also deleted my vMotion interface from my setup. Once all my networking met the requirements I removed the nodes and cluster from vCenter all together. I actually did not see this as a requirement in the documentation but it made sense to me as it is most likely cleaner.

I also was keen to see how well it would convert a virtual machine. I made sure I left a Windows 2012 R2 VM behind that was created from our standard template. One requirement for this is the install of the Nutanix Guest Tools. NGT is somewhat like VMware tools and provides enhanced functionality for the VM. It is key to AMF (App Mobility Fabric) and installs features such as file level restore, VSS Copy and Nutanix guest agent.

Install Nutanix Guest Tools

  • Go to table view under VM
  • Select your VM and enable NGT. You will be prompted to continue

  • This will mount the iso so log on to your VM and click setup under the CD-Rom drive

  • Agree to EULA and select install.
  • You will be prompted to install Python

  • Follow the bouncing ball

  • The mobility drivers will be installed as part of the installer

  • The setup is now complete

Nutanix has a video available that shows the above steps but it also shows how to install NGT on a Linux VM.

Before starting the actual conversion process I also deleted my existing protection domains and snapshots. Not sure if this was needed but seemed like a good idea.

Convert Cluster

  • Go to the gear icon and select Convert Cluster

  • Select the hypervisor and take note of the warnings

  • All going well you should get message that conversion was succesful

  • Click convert cluster to get started. A warning message will appear. Click yes

  • The conversion will start

  • Some progress bars will appear

At this point I was wondering if something was actually happening as I did not see any progress. After about 50 minutes I got kicked of the session and things went black for a wee while. Then things started happening and a progress screen appeared.

After 90 minutes the conversion appeared to be complete as indicated by this screen after logging in

Everything appeared to be in order with the system but I did get A1082 alerts for a while. The funny thing here was that they actually referred to vmnic while Acropolis names the interfaces Eth. I opened a job with support and this appears to be a red herring. The alerts appeared to have stopped about a day after conversion.

he system seemed to be just fine but what about the VM? It appeared in the list of VM's but I ran into a problem when trying to boot the VM. It was stuck at the boot disk as shown here.

It appears that the issue was caused by the fact that the original VM made use of EUFI boot. AHV does not support EUFI apparently with certain versions but it looks like it will be fixed in 4.7.1. I will be upgrading soon and hopefully that will kick the VM into life. It would have been good if the conversion process would have picked up on this non-compatibility beforehand.
I now have an AHV cluster and can't wait to get cracking. WIll spend some quality time with the best practices guide now. Expect to see some more posts on AHV soon.

No comments:

Post a comment