ESXi 4.0 to 4.1 Update Without vCenter

We recently needed to update our ESXi boxes from 4.0 to 4.1 to enable better support for USB devices (in particular flexlm HASP dongles).

Here are the steps to prepare for the update:

1. Download vSphere CLI - http://www.vmware.com/support/developer/vcli/
2. Download the update zip - https://www.vmware.com/tryvmware/p/activate.php?p=free-esxi&lp=1 (scroll down to "ESXi 4.1 (upgrade ZIP from ESXi 4.0)").
3. You will also need to download a new version of vSphere Client from http://vsphereclient.vmware.com/vsphereclient/2/5/8/9/0/2/VMware-viclient-all-4.1.0-258902.exe
4. Install the vSphere CLI.

Now to update:

1. First power off all of your virtual machines and then place ESXi into maintenance mode.
2. Upgrade esxupdate bulletin - open vCLI and change to the \VMWare VSphere CLI\bin folder and type the following:
   vihostupdate.pl --server [hostname/ip] -i -b [fullpath to update .zip] -B ESXi410-GA-esxupdate
   The process should run and state it was complete.
3. Upgrade bulletin - in the same vCLI window, type the following:
   vihostupdate.pl --server [hostname/ip] -i -b [fullpath to update .zip] -B ESXi410-GA
   The process should run and state it was complete.
4. Verify the installation by typing the following into the same window:
   vihostupdate.pl --server [hostname/ip] -query
5. Now reboot the ESXi host.
6. Now update the vSphere client before reconnecting to the ESXi box.

One last thing you will now need to do is re-register and get a new serial for the upgraded version, don't worry this is free.

See the release notes and the vSphere Upgrade Guide for more info.

UPDATE:

If you get the error: "No matching bulletin or VIB was found in the metadata.No Bulletin or VIB found with ID 'ESXi410-GA'" when running:

vihostupdate.pl --server [hostname/ip] -i -b [fullpath to update .zip] -B ESXi410-GA

Remove the -B ESXi410-GA option at the end.

New updated vSphere Client for the current version (4.1 Update 1):

http://vsphereclient.vmware.com/vsphereclient/3/4/5/0/4/3/VMware-viclient-all-4.1.0-345043.exe

Release Notes (4.1 Update 1):

http://www.vmware.com/support/vsphere4/doc/vsp_vc41_u1_rel_notes.html