With version 4.1 of ESX VMware discontinued the vSphere versions that were based on the Linux Kernel and started offering only vSphere ESXi editions of its popular Virtualization platform. If you are still running your virtualization on version ESX 4.1 or lower you need to upgrade to ESXi if you want to use vSphere 5.
There are 2 options to consider for the upgrade. You either rebuild your hosts from scratch to ESXi or you use the force migrate option that comes with ESXi 5. This tutorial is providing information on how to upgrade an ESX 4.1 host to ESXi 5 using the force migration feature accordingly. The benefits of this method are that all settings will be maintained and the host will be immediately operational after the upgrade. Please note that your vCenter will need to be running vCenter 5 before you attempt to upgrade your ESX host.
In this case the upgrade will be done using the install CD for ESXi 5. My vCenter was upgraded to vCenter 5 upfront and this tutorial is not providing the necessary steps for the vCenter upgrade.
Here are the upgrade steps one by one:
Start the installer and Accept EULA license agreement
Next step: The ESXi installer is going to scan the server
Scanning the existing system for information
Scanning found the existing installation on our system disk (2 x 136 GB Drives / RAID 1)
Scanning for existing VM ESX or ESXi installation
It discovered the ESX 4.1 installation and is offering 3 options to continue with
I selected the top option “Force Migrate ESX, preserve VMFS datastore”. Then the system continued scanning and discovered some 3rd party VIBs. “(Enter) Continue” is the only real option to continue.
Final scan of the system
All looks good. The installer confirms one more time that I want to do a force migrate operation from ESX 4.1 to ESXi 5.
The migration is in progress.
Almost there. The installer has discovered that the vpxuser password should be reset after the installation is completed (for security reason – read the message).
All done. The migration/upgrade to ESXi 5 was successful. You will need to upgrade your existing license key to version 5 in your account on VMWare’s website.
Let’s reboot this puppy and get the good stuff going.
All looks good. The server rebooted fine and the system comes up just fine. Host name and IP address (marked out for security reason on this picture) on the splash screen show that nothing has changed.
From these steps you can see that the migration from ESX to ESXi using the ESXi 5 installer CD-ROM is straight forward and easy. I have done this on several hosts with no issues. The overall process took about 10 – 15 minutes per host. After the reboot all I had to do in vCenter was to reconnect the host and life was good. HA was complaining initially, but happens quite often when you take an existing host and replace it or upgrade it to a newer version.
In a future tutorial I will show a clean install of ESXi on an existing ESX host and rebuild it from scratch. For another VMWare tutorial I am planning on talking about how to script the installation and configuration. While VMware offers some tools for that, fact is that these options are only available for the Enterprise Plus licenses and there are many ESX/ESXi installation out there that do not have this. I wish VMware would change that because it really puts a dent into their reputation (at least that is my opinion). Small to mid-size businesses and even larger corporations to a certain degree do not want to pay the premium that VMware requires for the Enterprise Plus licenses. But as you will see – there are easy ways around this.