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Once your image is created, it can be used to build new clusters with the exact same specifications (if, of course, those clusters have the same hardware characteristics). Imagine a supermarket chain with 200 shops around the country, and your task is to build and maintain those three-node vSAN clusters for all those sites. Cluster images to the rescue.
This is something that many admins were looking for. Many of us know that, for example, within a vSAN environment, it's pretty crucial to have the same level of firmware/driver combination on all HCAs within clusters.
ESXi 7 with cluster imaging allows you to maintain a consistent configuration across infrastructure by bundling an ESXi base image with firmware, vendor, and driver add-ons.
The requirements
- ESXi and vSphere 7.
- Within your inventory, you'll have to have a datacenter cluster. Normally it's obvious, but make sure they have been created.
- All ESXi 7 hosts must be on the same version.
- You must know the ESXi root account password.
The steps
When you open your vSphere client, go to Home > Hosts and Clusters. Select a data center, right-click it, and select New Cluster. Enter a name for the cluster.
Create a new cluster in vSphere 7
Next, pick the features that you'll be using within your cluster (DRS, HA, vMotion, vSAN, etc.), and select the checkbox for Manage all hosts in the cluster with a single image.
Manage all ESXi 7 hosts with a single image
Note: The vendor add-on is optional. You may use this perfectly well without the server on the list too.
The ESXi 7 images have four elements
ESXi Base Image—This is the ESXi release version ISO image which was released by VMware. It has all the necessary components of the VMware ESXi Server and additional components such as drivers and adapters that are necessary for installation.
Vendor Add-on—This is a collection of software components provided by the OEM manufacturer. It's the manufacturer's responsibility to provide and maintain an up-to-date version, which is usually distributed within MyVMware downloads. This vendor add-on usually has some drivers, patches, and management solutions.
Firmware and Driver Add-on—This one is a highly specific package that helps with the firmware updates. The firmware and driver add-on combination is crucial for specific types of hardware, such as HBAs, and usually has firmware for a specific server version.
Component—This one is basically the smallest part of the image and is reserved for third-party software vendors. VMware and OEM manufacturers do not publish components, as they're usually very small pieces of software that contain small drivers, but independently from everything else. This enables you to fine tune your image and add even very small components to it.
Your image is now created but you can go back to edit the options
If you want to add/remove the different vendor add-ons or change them, click the Edit button as shown above. This will bring back the assistant.
Once you're happy with your image and selection of firmware, drivers, and ESXi version, you can add hosts that you have preinstalled.
You can export the ESXi 7 cluster image
When you click the Export option, the assistant gives you three options to choose from:
- JSON—Allows you to use this file in other clusters that are managed by images. It does not contain all the base installation files, just the JSON configuration file. Remember that you can still have clusters that are not managed by images, but as traditional compliance levels.
- ISO—This gives you a full-blown ISO with everything in it. You can easily upload this to some cloud storage and use it for other clusters where you'll be able to access it from anywhere.
- ZIP—Create an offline bundle that can be imported by vSphere Lifecycle Manager. Similar to ISO.
Export as JSON ISO or ZIP fil
In our lab case, we haven't added any hosts, so we cannot show you the compliance tab. But as you can imagine, this will be very easy to manage.
Next to the Check Compliance link, click the ellipsis button to show the menu. You can select Edit remediation settings to have a look at the cluster remediation options.
Image compliance options allow you to verify whether your hosts are in compliance
The overlay window pops up with some options, which are basically the same as when you manage your cluster via baselines. These are cluster-level update settings and settings concerning your VMs, such as whether you want your VMs to be powered off, without change, or suspended.
If you have vMotion configured and you keep the default selection, Do not change the power state, your VMs are simply migrated via vMotion to other hosts within the cluster, and the host enters maintenance mode before starting the update.
Edit cluster remediation settings
As you can see, we can enable quick boot functionality, which allows you to bypass the hosts' firmware boot and speed up the overall remediation on clusters.
Final words
If you have hardware supporting vSphere 7 and ESXi 7, using cluster images to maintain the cluster's integrity and firmware/add-ons is a perfect strategy moving forward. Older hardware that does not support vSphere 7 has to be maintained as before, via baselines.
You can test a host if you can run ESXi 7 and then change the traditional cluster management from baseline-based management to image-based management. So yes, it's possible, with the condition that your hardware can run ESXi 7.
The OEM vendors always release their add-ons late, after the ESXi 7 release. So be patient here and check back with your hardware vendor whether the version of your ESXi release is supported or whether there are some new add-ons so you can start using vSphere 7 and ESXi 7 cluster images within your organization.
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This article is part of a large series of articles teaching toward the VCP-DCV 2020 exam. The study guide, available here VCP7-DCV Study Guide – VCP-DCV 2020 Certification, helps you master all topics to become VMware Certified.
Are you sure that vMotion is enough ?
What about DRS and automation level?
Hi Dominik, can you rephrase your question? Not sure I understand where you’re heading.
” …If you have vMotion configured and you keep the default selection, Do not change the power state, your VMs are simply migrated via vMotion to other hosts within the cluster, and the host enters maintenance mode before starting the update…”
In yor text it sounds like you don’t need DRS (only configured vMotion) and everything will happen automatically.
Oh, I see. Correct, DRS must be ON….. “To ensure availability, you can enable DRS for
the cluster and you can configure it for vSphere vMotion. In this case, before the host is put in
maintenance mode, vCenter Server migrates the virtual machines to another ESXi host within the
cluster”.
to follow up with the DRS point, if you don’t have DRS (e.g. VMware Essentials Plus), then “Remediate ALL” will hang waiting for DRS.
You need to manually place each host in turn into Maintenance mode, then you can select each host in turn and choose Remediate (from the Action menu to the right) .