Changing The Controller VM IP Addresses In Your Nutanix Cluster (CLI Script)

  • 9 September 2020
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Before you begin

  • Before you decide to change the CVM, hypervisor host, and IPMI IP addresses, consider the possibility of incorporating the existing IP address schema into the new infrastructure by reconfiguring your routers and switches instead of Nutanix nodes and CVMs. If that is not possible and you must change the IP addresses of CVMs and hypervisor hosts, proceed with the procedure described in this document.

  • Guest VM downtime is necessary for this change, because the Nutanix cluster must be in a stopped state. Therefore, plan the guest VM downtime accordingly.

  • Verify if your cluster is using the network segmentation feature.
    nutanix@cvm$ network_segment_status
    Note the following if you are using the network segmentation feature.

    1. The network segmentation feature enables the backplane network for CVMs in your cluster (eth2 interface). The backplane network is always a non-routable subnet and/or VLAN that is distinct from the one which is used by the external interfaces (eth0) of your CVMs and the management network on your hypervisor. Typically, you do not need to change the IP addresses of the backplane interface (eth2) if you are updating the CVM or host IP addresses.

    2. If you have enabled network segmentation on your cluster, check to make sure that the VLAN and subnet in-use by the backplane network is still going to be valid once you move to the new IP scheme. If not, and change the subnet or VLAN. See the Prism Web Console Guide for your version of AOS to find instructions on disabling the network segmentation feature (see the Disabling Network Segmentation topic) before you change the CVM and host IP addresses. After you have updated the CVM and host IP addresses by following the steps outlined later in this document, you can then proceed to re-enable network segmentation. Follow the instructions in the Prism Web Console Guide, which describes how to designate the new VLAN or subnet for the backplane network.

  • If you have configured remote sites for data protection, either wait until any ongoing replications are complete or abort them. After you successfully reconfigure the IP addresses, update the reconfigured IP addresses at the remote sites before you resume the replications.

  • Nutanix recommends that you prepare a spreadsheet that includes the existing and new CVM, hypervisor host, and IPMI IP addresses, subnet masks, default gateway, and cluster virtual IP addresses and VLANs (download the IP Address Change Worksheet Template).

  • You can change the virtual IP address of the cluster either before or after you change the CVM IP address. The virtual IP address of the cluster is required to configure certain data protection features. Do the following to change the virtual IP address of the cluster.Caution: All the features that use the cluster virtual IP address will be impacted if you change that address. See the "Virtual IP Address Impact" section in the Prism Web Console Guide for more information.

    1. Clear the existing virtual IP address of the cluster.
      nutanix@cvm$ ncli cluster clear-external-ip-address

    2. Set a new virtual IP address for the cluster.
      nutanix@cvm$ ncli cluster set-external-ip-address external-ip-address=insert_new_external_ip_address logon-name=admin password=prism_admin_user_password
      Replace insert_new_external_ip_address with the new virtual IP address for the cluster.
      Replaceprism_admin_user_password with password of the Prism admin account.

Following is the summary of steps that you must perform to change the IP addresses on a Nutanix cluster.

  1. Check the health of the cluster infrastructure and resiliency (For more information, see the Before you begin section of this document.)

  2. Stop the cluster.

  3. Change the VLAN and NIC Teaming configurations as necessary.Note: Check the connectivity between CVMs and hosts, that is all the hosts must be reachable from all the CVMs and vice versa before you perform step 4. If any CVM or host is not reachable, contact Nutanix Support for assistance.

  4. Change the CVM IP addresses by using the external_ip_reconfig script.

  5. Change the hypervisor host IP addresses if necessary.

  6. Restart the CVMs.

  7. Perform the initial series of validation steps.

  8. Start the cluster.

  9. Perform the final series of validation steps.

  10. Change the IPMI IP addresses if necessary.

The external IP address reconfiguration script performs the following tasks:

  1. Checks if cluster is stopped.

  2. Puts the cluster in reconfiguration mode.

  3. Restarts Genesis.

  4. Prompts you to type the new netmask, gateway, and external IP addresses, and updates them.

  5. Updates the IP addresses of the Zookeeper hosts.

Detailed documentation:

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