Nutanix In-Place Hypervisor Conversion | ESXi – AHV

Nutanix has one more great feature that is called Nutanix In-Place hypervisor / cluster conversion from VMware ESXi hypervisor to Nutanix AHV and vise-versa ( Convert back from Nutanix AHV to VMware ESXI hypervisor ) on Nutanix cluster. This unique feature gives you to freedom to change your currently running VMware ESXi hypervisor any time on fly if want to wish to use Nutanix AHV hypervisor on Nutanix cluster.

Note: This hypervisor conversion option only supported by Nutanix – No other vendor support it till today.

Perform the following procedure to convert the Nutanix ESXi cluster to Nutanix AHV. Perform this procedure only if you have converted your cluster from ESXi to AHV.

Requirements and Limitations for In-Place Hypervisor Conversion

Following are the general prerequisites along with requirements and limitations for the in-place hypervisor conversion feature from VMware ESXi hypervisor to Nutanix AHV hypervisor on the Nutanix cluster.

Prerequisites

These are the prerequisites of Nutanix VMware ESXi cluster must meet before In-Place conversion of hypervisor, From VMware ESXi to Nutanix AHV hypervisor.

• HA and DRS must be enabled.
• All the hosts should be managed by the same vCenter Server.

• The vCenter Server VM that is managing the cluster must not be on the same cluster which is being converted.

• Install NGT on all the VMs. See Nutanix Guest Tool NGT Installations in Windows and Linux VM for more information.

• All the platforms are supported.

• Ensure that you have saved all the ESXi ISOs (if you have more than one version of ESXi running in your cluster) at the foundation/isos/hypervisor/esx/ location. This ISO image or images are used to bring the cluster back to its pre-conversion state if you abort the cluster conversion operation from ESXi to AHV.

• Recommended Nutnaix AOS version is minimum 5.5 and later. see Nutanix End of Life Announcement VMware vSphere 5.5

Read also: VMware Esxi 6.5 U1 High CPU Consumption issue

General Limitations

These are general limitations of cluster conversion from VMwar ESXi cluster to Nutanix AHV cluster:

• This feature is not supported if you have metro availability protection domains in your environment.

• Nutanix nodes must be imaged by VMwar ESXi hypervisor to convert the VMware ESXi to AHV and vise-versa.

• Conversion back from ESXi to AHV fails if you have converted the cluster using free ESXi license.

• Cluster conversion does not proceed if you have Nutanix Files deployed in your cluster.

• Affinity policies (if any configured) are not honored post conversion to Nutanix AHV.

• This feature is not supported for single-node clusters and two-node clusters.

Read also: Nutanix Two-nodes cluster Vulnerability

ESXi Supported Versions

Following VMware ESXi hypervisors are supported by Nutanix platform:

ESXi Network Requirements and Limitations

Read also: Nutanix HCI Infra Network Port List

• The vSwitch is converted to an open vSwitch on the AHV side. If you perform any configuration changes on the AHV, these changes may not be maintained after converting the cluster back to ESXi.

• Networks with no VMs prior to the cluster conversion may not be converted.

• All the VMs may end up on a single host during reverse conversion. The network configuration that you might have defined for the VMs may not be maintained.

• MAC address of the VMs are not preserved because the MAC address is provided by the hypervisor (ESXi and AHV) and both the hypervisors follow different conventions.

• After migration to AHV, NIC adapter may not have same type of virtualized hardware device (for example VMXNET3 may be E1000 after conversion).

• Serial ports and virtual graphics processing unit (vGPU) configurations may be lost after conversion.

Virtual Machine Requirements and Limitations

• Only VMs with flat disks are supported. The delta disks are not supported.

• IDE/SCSI disks are only supported. SATA and PCI disks are not supported.

• Set the SAN policy to OnlineAll for all the Windows VMs for all the non-boot SCSI disks so that they can be automatically brought online. For more information about setting SAN policy, see Bringing Multiple SCSI Disks Online.

• Folders with NFS mounts and VMware tags in vSphere for categorisation may not be supported.

• Ensure that you do not have VMs with UEFI boot firmware enabled.
• Virtual machines with attached volume groups or shared virtual disks are not supported.

• After conversion of the cluster back to ESXi from AHV, the VMs are converted to the maximum hardware version that is supported by that specific ESXi version.

• Guest OS network interface on Linux VMs may change to generic type during ESXi to AHV conversion (for example, in RHEL 7 network interface enoXXXX changes to eth0). You have to reconfigure the network settings according to changes post conversion.

• Guest OS type for the Linux VMs may change to a more generic type (for example RHEL 7 may change to Other Linux 64-bit) during the conversion back from AHV to ESXi.

Supported Operating Systems

Begin Hypervisor Conversion | ESXi – AHV

Verify that you have met all the networking and virtual machine requirements as described above.

Now follow the Hypervisor conversion from currently running ESXi hypervisor to Nutanix AHV hypervisor on Nutani platform.

• Log into the Nutnaix Prism web console.
• Click the gear icon in the main menu and then select Convert Cluster in the Settings page.

• From the Available Hypervisor drop-down menu, select Nutanix AHV.

• Select the state of the VMs that you want post conversion from the VM Boot Options drop-down menu.
  • Preserve power state of the user VMs: Select this option if you want to keep the original power state of the VMs. For example, if you want the VMs to be in a running state post conversion automatically, select this option.
  • Power Off User VMs: Select this option if you want power off all the VMs running on ESXi cluster before you start the conversion process. After conversion, these VMs will be in the powered off state.

• Click Validate to enter vCenter Server credentials and to verify whether you have met all the requirements.

• Enter the IP address of the vCenter Server in the vCenter Sever IP Address along with the administrator user name and password of the vCenter Server in the Username and Password fields. if required.

• Click Yes.A validation that you have met all the requirements is performed. Once the validation is successful the conversion process proceeds. If validation fails (for any reason), a relevant message to take appropriate action is displayed.

• Click Convert Cluster button to start the conversion process.

• (Optional) If you have not saved the ESXi ISOs at the foundation/isos/hypervisor/esx/ location, click Choose File and select the ESXi ISO.
  
  Note: If you have different versions of ESXi running in your cluster, you have to perform this step for every version of ESXi ISO.

• Click Convert. All cluster operations stops and you will not be able to perform any operations on the cluster while the conversion is in progress. A message to this effect is displayed.

• Click Yes to proceed with the conversion.The conversion begins. The time taken to finish the conversion is dependent on your environment. For example, it might take between 2 to 3 hours for the conversion to finish for a 3 or 4 nodes cluster. However, the VM downtime will be less than 5 minutes after cluster conversion.

Video Tutorial

You have to follow above described prerequisites, limitaions, steps to convert the Nutanix VMware ESXi cluster to Nutanix AHV cluster.

Conclusion

I hope, you have learned the way to convert the VMwar ESXi hypervisor cluster to Nutanix AHV cluster if you are not interested to use the VMware ESXi hypervisor any more and/or your VMware ESXi license has got expired, Nutanix AHV hypervisor is best option to opt because Nutanix AHV hypervisor is free to use with updates.

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