This article explains how to update a standalone (i.e. not managed by vCenter) ESXi host to a later version.
Enable Remote Shell Access
In this example I am connecting to the ESXi server remotely. Alternatively you could run this from the ESXi shell via the console. Logon to the ESXi server via the vi client and go to configuration – security. Firstly start the SSH service.
Secondly make sure the “SSH server” service is running.
Update the ESXi server
You should now be able to SSH to the ESXi server. In this example I am using putty as an SSH client.
Allow outbound HTTP access
esxcli network firewall ruleset set -e true -r httpClient
To view a list of ESXi versions to download enter the command
esxcli software sources profile list -d https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml
Choose the version you want to install. In this example we want the latest version – ESXi-5.5.0-20140704001-standard. Enter the below command to download and install (substituting the version as appropriate
esxcli software profile update -d https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml -p ESXi-5.5.0-20140704001-standard
Once complete you will be prompted to reboot. Once you have rebooted the system is ready to use.