My experiences upgrading ESX 3.5 to vSphere 4.0

Published On: 2009-09-14By:

A couple of weeks back I begun the process of upgrading our VMware ESX 3.5 systems to vSphere 4.0.  I’ve got to tell you, that has to be the easiest system upgrade process in history.

The Virtual Center server took a little bit to get upgraded since there are so many components which need to be upgraded on the machine.  Once they were all upgraded upgrading the ESX hosts was a piece of cake.

When you install the upgraded client tools on your machine the last step asks you if you’d like to install the host upgrade tool.  This upgrade tool is fantastic.

You tell it which host you want to upgrade, and you point it to the vSphere ISO that you want to install on the host, in my case VMware ESX 4.0.  After that you answer a couple of questions about how big you want the host’s volume to be where it installs, and that’s it.  The tool uploads the ISO to the host, and when the upload is complete it begins installing the OS automatically.  In the event of a failure the host will rollback the upgrade and continue to be running the prior OS.

One massive change between VI3 (ESX 3.x) and vSphere 4.0 is the licensing changes between the two.  With VI3 you download a license from from VMware and load that License file into a licensing server on the Virtual Center host.  With vSphere you add license keys to the Licensing section within the vCenter Server via the vCenter client.

I’d have to say, the entire process was very easy.  It took me about 2 hours per host to upgrade (there was a slow 10Mbit WAN connection between the Hosts and the client machine I was running the upgrade from.

So far I’ve upgraded my standalone ESX machines which handle the non-customer facing machines at the office (domain controllers, file servers, dev and QA app servers, etc).  The only task I have left is to upgrade the production customer facing ESX cluster which that handle our websites, DNS servers, etc.

Hopefully the cluster will upgrade just as easily as the standalone hosts.


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5 responses to “My experiences upgrading ESX 3.5 to vSphere 4.0”

  1. BrianTkatch says:

    last sentence 5th paragraph “With vSphere you add license keys tot he” should be “to the”.

  2. Ubersol says:

    Is there any documentation you followed during the upgrade process?

  3. mrdenny says:

    Yes. Here’s a link to [A href=””]part 1[/A] and [A href=””]part 2[/A] of a blog post I found. Here’s the link to the [A href=””]official upgrade gude [/A]as well (pdf).

  4. Jonelo says:

    Hi Denny,

    Did you encounter any interruptions/issues to your production VMs (Windows 2000, 2003, 2008, XP, & Red Hat) during & or after the upgrade?


  5. mrdenny says:

    I didn’t have any issues when doing my upgrades. The only outages to the guest OSs were the upgrades of the VMware Tools which required the guest to reboot. Then powering off the guest and upgrading the virtual hardware version from 4 to 7. After the VM powered up this required another reboot of the guest. Total downtime per guest OS would be less than 5 minutes (dependind on how long it takes to reboot each guest).


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