One of the things that some of the Microsoft Hyper-V users tout is that Hyper-V is free. Sometimes, like in smaller offices or branch locations, it may even make sense to use Hyper-V where there are four or less VMs on a host. The Windows 2008 Server Enterprise Edition license will allow for the base Hyper-V installation and up to four Windows 2008 Server VMs on the hardware. But there are many valid reasons to run VMware’s vSphere Hypervisor, the free version of ESXi in your datacenter.
Why use vSphere Hypervisor
The vSphere Hypervisor is the same ESXi bare-metal hypervisor as what comes with all of the other editions. Using the free version will shut off some of the features available in the paid versions, but the vSphere Hypervisor still has many features not offered by Microsoft Hyper-V. Unless you are already using Microsoft System Center and Virtual Machine Manager, you may want to take a second look at ESXi.
Features of vSphere Hypervisor
- Even the free version of ESXi offers a higher consolidation ratio than Hyper-V because the CPU scheduler and memory technologies, like Transparent Page Sharing are enabled in all versions of ESXi.
- The ESXi hypervisor has a much smaller footprint (144MB) than Hyper-V (3GB), even in the free core mode. A larger footprint means a larger attack area.
- ESXi uses a rigorously tested driver set. Hyper-V uses generic Windows drivers, that are sometimes difficult to set up using the Hyper-V Core Mode interface. These drivers are usually the most common reason for the BSOD.
- ESXi actually supports more versions of Windows than Hyper-V supports. It also supports more versions of Linux as well as OS-X Server, FreeBSD and Solaris.
- ESXi allows for thin provisioning of VM disks.
- ESXi allows you to use shared storage (single path only!). Hyper-V requires an Enterprise Edition license.
- ESXi can be easily upgraded to unlock the features of any paid version by simply entering a new license key.
What’s Missing in vSphere Hypervisor
- No advanced or enterprise features, such as vMotion, DRS, DPM, VM Templates, Autodeploy, etc.
- Can only be managed using the vSphere Client connected directly to the ESXi host. No management via vCenter server.
- Using PowerCLI or vCLI only allows for read-only functionality. You can’t use those cool scripts.
- Physical RAM capped at 32GB per host.
- Virtual CPUs capped at 8 per VM.
- No vSphere Distributed Switch.
- No storage multipathing.
- No vADP features means limited backup capabilities. But you can use backup agents inside the guest OS.
Licensing vSphere Hypervisor
If you download an ESXi image, all of the features are turned on by default. VMware gives you a 60-day evaluation license so that you can try all of the features before you decide which ones you want. I suggest that you try all of the features for a while before you make the final decision to use the free version. Whether you already have ESXi running or just want to get a copy, use the following instructions to get the free key.
Register and Download vSphere Hypervisor and the License Key
Start out by visiting http://www.vmware.com/go/get-free-esxi
If you don’t already have an account, click on the “Create an Account” tab and enter your information. If you already have an account, use the “I have an Account” tab and log in.
If you are registering for the first time, enter your contact information. Then enter the number of hosts you plan to use and accept the EULA. Click on the “Register” button.
If you already have an account, enter the number of hosts you plan to use and accept the EULA. Click on the “Register” button.
Scroll down on the new page and you will see your license key and links to download ESXi and the vSphere Client. I would suggest you download the image created by your hardware manufacturer if available. This will typically include all of the required hardware drivers as well as any customized CIM providers needed to display extended hardware health information.
Install ESXi on your server hardware
Either burn a CD from the ISO image you downloaded or use the remote console such as iLo to directly mount the image. The actual steps for installing ESXi on your hardware is not in scope of this document.
You will also need to install the vSphere Client on a Windows system if you have not already done so.
Applying the License Key to ESXi
Log into the ESXi host by connecting the vSphere Client directly and follow the steps below to add the vSphere Hypervisor key.
Click on the Configuration tab. Under Software, click on the Licensed Features link. Notice that all of the Product Features are enabled in Evaluation Mode. Click on the Edit link.
In the Assign License dialog, click on the Enter Key button.
Enter the new license key and click OK.
Confirm the license key appears with the proper features. Click OK.
Confirm that the free features are enabled and that the key never expires.
That is it. You have successfully applied the free license to the vSphere Hypervisor.