Upgrade an ESXi 4.0 Host to 4.1 with the vihostupdate Utility
1. Check for a scratch partition in the Software Advanced Settings in the Configuration tab of the vSphere Client. If one doesn’t exist configure one and reboot the host before proceeding with the upgrade. (See here for more info)
2. Download and install the VMware vSphere command line interface. (vSphere CLI)
3. Download the upgrade-from-ESXi4.0-to-4.1.0-0.0.build#-release.zip by clicking the VMware ESXi 4.1 Installable option. Save it on the machine with the vSphere CLI installed on it.
4. Power off running machines and place host in maintenance mode.
5. Install the bulletin by running the following from the vSphere CLI. CD “C:Program FilesVMwareVMware vSphere CLIbin” Vihostupdate.pl –server_ host_name_of_ IP_address -i -b location_of_the_ESXi_upgrade_ZIP bundle – B ESXi410-GA-esxupdate Enter username and password when prompted for it by the ESXi host
6. Install the upgrade bulletin by running the following from the vSphere CLI Vihostupdate.pl –server host name or IP address -i -b location of the ESXi upgrade ZIP bundle -B ESXi410-GA Enter username and password when prompted for it by the ESXi host
7. Verify that the bulletins are installed on the ESXi host by running the following. vihostupdate.pl –server host name or IP address –query
8. Reboot the host