Quick Tip - How to download ESXi ISO image for all releases including patch updates?

Not all ESXi releases, including patch updates are available as an ISO image that can be downloaded. Depending on the type of ESXi release, it will either be available as an ISO and Offline Bundle (zip) format which can downloaded from the ESXi Customer Connect portal or only as an Offline Bundle which must be downloaded from the VMware Patch portal.

I typically see folks forgetting about the VMware Patch portal, which also provides patch updates for the vCenter Server Appliance (VCSA), when they are searching for a new ESXi updates. Let's take a look at an example using the ESXi 7.0 Update 3 release, as you can see from the screenshot below, you can download 7.0 Update 3c, d, f and g from the Customer Connector portal but for 7.0 Update 3e, i, j and k you will need to use the VMware Patch portal.

As mentioned earlier, when downloading ESXi patches from the VMware Patch portal, they are only available in the Offline Bundle format, which might work for most typical patch use cases but in some scenarios, you may actually want it in an ISO format, especially for initial installation.

While you can certainly download the Offline Bundle and then export the image profile to an ISO format, it does take several steps and there are few ways to streamline this for those looking for an easy way to get an ISO image.

UI Method:

If you have vCenter Server 7.0 or later, you can simply use vSphere Lifecycle Manager (vLCM) to create a "dummy" vSphere Cluster and specified the desired ESXi version and then export the image to ISO which you can then download. For more details, please see THIS blog post.

a https://williamlam.com/2022/02/how-to-create-a-customized-esxi-iso-without-vcenter-server.html

CLI Method:

The UI method is great if you already have a vCenter Server running but what if you have no existing infrastructure, well this is where CLI method will come in handy and may even be be faster.

Step 1 - Install the latest release of PowerCLI if you have not already, this is especially important for those interested in ESXi 8.x as there are new changes to creating

Step 2 - Find the build number for the desired ESXi version using VMware KB 2143832. In our example, we will use ESXi 7.0 Update 3i which has build number of 20842708

Step 3 - Run the following command, which can take some time, to list out all available ESXi releases from VMware's online depot and search for the full version string based on the build number retrieved from the prior step.

Get-DepotBaseImages https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml

In our example, ESXi 7.0 Update 3i will mapped to version string labeled 7.0.3-0.65.20842708

Step 4 - Finally, we create the desired JSON specification that contains the desired ESXi version and then we use the New-IsoImage cmdlet to generate the ISO image, which we have named ESXi-7.0u3i-20842708.iso

$spec = [ordered] @{
    base_image = @{
        version = "7.0.3-0.65.20842708"
    }
}
$spec | ConvertTo-Json | Set-Content -NoNewline -Path spec.json

New-IsoImage -Depots https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml -SoftwareSpec spec.json -Destination "ESXi-7.0u3i-20842708.iso"

At this point, you now have an installable ESXi ISO image for the specific ESXi patch release. If you need to add additional VIB/Components, you can refer to THIS blog post for the required commands to incoroprate additional drivers.