With vSphere 5, vihostupdate and esxupdate are not applicable for ESXi 5. We instead need to use the esxcli command to apply the updates to our ESXi 5 hosts.

• Make sure you have ESXi Shell access on the ESXi 5 host
• Download the patch bundle directly from the VMware Support Website (http://www.vmware.com/patchmgr/download.portal). This download will be a .zip file. Do not extract it!
• Upload the .zip file to a datastore that is accessible on the ESXi host you wish to update. The syntax below will use /vmfs/volumes/pool01, and you may need to adjust this as necessary. Note that the .zip file is uploaded to the ESXi host via the vSphere Client.
• Set the host to maintenance mode via the vSphere Client
• To verify which VIBs are already installed on the ESXi 5 host, issue the following command.
  esxcli software vib list | more
• To find out which VIBs are available in the depot (the downloaded .zip file), issue the following command.
  esxcli software sources vib list --depot=/vmfs/volumes/pool01/updates/ESXi500-201109001.zip | more
• To update the ESXi 5 host with the VIBs included in the depot, issue the following command.
  esxcli software vib update --depot=/vmfs/volumes/pool01/updates/ESXi500-201109001.zip
• When the update is complete, verify the information presented. If prompted, reboot the ESXi 5 host (via vSphere Client)
• If applicable, take the ESXi 5 host out of maintenance mode using the vSphere Client