Upgrading i3.metal to i7i.metal-24xl bare metal instances in an NC2 Cluster

Introduction

The i3.metal AWS EC2 bare metal instance has been a popular choice for many Nutanix Cloud Clusters (NC2) customers. Supported at launch for NC2, i3 provided just the right amount of CPU, RAM and storage for many early customers, and was available across a large range of AWS regions.

However, all good things must come to an end. With the i3.metal entering into its 8th year of availability there are larger, more performant instances now available. Those instances will be supported long after i3.metal has been retired by AWS, so it’s worth considering those options now.. 

One of those instance types is the i7i.metal-24xl. AWS have been gradually increasing the availability across their regions of the i7i.metal-24xl instance, and Nutanix has followed that availability by adding support to NC2. You can see availability here.

The delta between the Intel processor family in i3 (Broadwell) and i7i (Emerald Rapids) is quite significant, given that there are 4 Intel CPU generations between them. This means that to upgrade a cluster's hardware from i3 to i7i, we need to use an intermediary instance type to bridge the processor delta. Luckily, with NC2’s broad support for AWS instance types, we have two options to do that, either i3en or i4i. The NC2 portal will provide for a seamless transition, designed to migrate virtual machines between hosts without requiring a reboot, maintain IP addresses for management endpoints such as Prism Central, and allow tooling integrations (e.g. backups, monitoring) to remain the same.

Changing capacity and instance types in an NC2 cluster is straightforward. For a cluster with light usage, the replacement process takes about two hours. For a more heavily used cluster, the process may take longer and you should plan any associated change windows accordingly. You should also consider making this change outside of peak times and also outside of times when storage throughput is increased, such as during nightly backup windows.

Let’s dive into the steps.

Steps

1. Log in to the NC2 Portal and click on the cluster that you want to migrate from i3.
2. Before proceeding with the capacity change, we need to validate that the cluster is running on a version of AOS that is supported by the newer instance type. On the Cluster Summary page, review the Nutanix Software Panel. Check that the cluster is running on AOS 7.0.1.7 or later. If the cluster is currently running an older version of AOS, the cluster will need to be upgraded to AOS 7.0.1.7 or later before proceeding. Learn more about the Nutanix Software Update process over at our documentation portal.

3. Once you have confirmed the AOS version is 7.0.1.7 or higher, click Settings > Capacity.

4. Under Cluster Capacity, we are able to add and remove instances at the same time. The NC2 Portal orchestration engine will automatically figure out the right steps to perform, such as adding new instances first before removing old instances. First click "Add Host Type +".

5. Under Host Type select either i4i or i3en and add the same number of hosts to match the current Nr of Hosts. DO NOT CLICK Save just yet.

6. Under the i3.metal section, click the "-" button until the Number of Hosts is listed as 0.

7. Before completing the change, review the Cluster Capacity summary to check that sufficient capacity will remain for your workloads. Once you are confident the capacity is correct, go ahead and click Save.
8. You can track the progress of this change under Tasks, and also monitor the changes under Hardware > Hosts tab. In addition to using the NC2 Portal to monitor these changes, you can also observe the changes happening in the AWS console, under EC2.

9. Once the task has completed, the next step is to move from i3en/i4i to i7i.metal-24xl. Click on Settings > Capacity to return to the Cluster Capacity page.
10. We’ll repeat the same process as before. Click Add Host Type, and then under Host Type select i7i.metal-24xl. Add the same number of hosts to match the current Nr of Hosts. Again, don’t click on Save just yet.

11. Under Host Type, reduce the number of i3en/i4i hosts down to 0. Then click Save.

12. Again, you can monitor this process under Tasks. You can also see the instance changes under Hardware > Hosts, and in the AWS Console under EC2.

13. Once the process completes, you’ll have a cluster that is no longer running i3 and has transitioned to using i7i.metal-24xl.

Summary

What the above process demonstrates is the power of NC2.  Even for the most difficult hardware upgrade, covering 5 generations of Intel CPUs, what would be weeks of procurement and data center activity is reduced to a few clicks.  You can sit back and watch the automation do its magic whilst all of your VMs and data seamlessly move to the latest and greatest hardware, before collecting the plaudits from your users who will likely notice everything running even faster.  Or just enjoy that they didn’t notice a thing.

These things can be viewed in the video below, or by clicking here.

For more information on Nutanix Cloud Clusters (NC2) on AWS click here.

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