ESXi 5 Tips & Tricks: Disable Tech Support Mode Warnings

ESX is officially gone and VMware has made the succession to ESXi complete. Still, some of us might want to log into ESXi's shell by enabling Tech Support Mode or Remote Tech Support via SSH. Now by enabling one of these two support modes, a yellow warning will appear on the host object in vCenter. If you select the Summary tab of the actual host itself, you will see a couple of messages that are immediately apparent:

• ESXi Shell for the host has been enabled
• SSH for the host has been enabled

In VMware's defense, it most certainly didn't enable those warning just to annoy us. Enabling Shell and SSH remote access should be used for a limited time for technical support purposes. Security best practices dictate that you keep these disabled--hence, the warning messages. Administering or managing your ESXi host from the command line should be done using the vSphere Management Assistant appliance (vMA) or by installing PowerShell.

That being said, some of us understand the security risks and still want to enable shell access or remote access via SSH, but do not want to see the annoying warning messages that are there just to disturb our perfectly harmonious and well-oiled vSphere infrastructures. To those vNerds I give you three ways of disabling these warnings:

1. Command line:
   esxcli system settings advanced set -o /UserVars/ESXiShellTimeOut -i 1
2. Scripted installs you set:
   /adv/UserVars/SuppressShellWarning = "1"

The third method is through the GUI, as follows:

1. Select your ESXi host and go to the Configuration tab (yes, it has to be done on every host, so use scripted installs to set this if you will deploy on all hosts as a standard)
2. Click on the Advanced Settings node on the left
3. Select the UserVars node on the left
4. Locate "UserVars.SuppressShellWarning" and set the value to 1. (By default, it is set to 0.)

You can disable the warning messages without rebooting the ESXi host or placing it in maintenance mode. For more information about this, check out VMware KB 2003637.

Posted by Elias Khnaser on 09/15/2011 at 12:49 PM