Upgrade ESXi 3.5 to 4.1 summary:
- upgrade ESXi 3.5 to 4.0 Update 1
- upgrade ESXi 4.0 Update 1 to 4.1
- I cannot upgrade EXSi 3.5 to 4.1 directly using Host Update Utility
Upgrade procedure:
- Download “VMware vSphere Client and Host Update Utility 4.0 Update 1”. (VMware vSphere Client 4.1 download package does not include Host Update Utility)
- Install VMware vSphere Client and Host Update Utility 4.0 Update 1.
- Download “Upgrade package from ESXi Server 3.5 to ESXi Server 4.0 Update 1” ZIP package.
- Launch Host Update Utility 4.0 to upgrade ESXi Server 3.5 to 4.0 Update 1 with the ZIP package. This will upgrade ESXi to 4.0.0 build-208167.
- Then follow the instruction on “Upgrade vSphere ESXi from 4.0 to 4.1 Using vihostupdate”