When you enable the ESXi Shell or SSH on a particular host in a vSphere cluster, a warning will appear on a ESX host:

Note that prior to vSphere 4.1 Update 2, it is not possible to suppress the warnings.

vSphere Client

1. Open vSphere Client.
2. Select the ESX host. From the Configuration tab (right pane), click Advanced Settings.
3. Navigate to UserVars → UserVars.SuppressShellWarning.
   Set its value to 1.
4. Click OK to confirm. The warning will disappear immediately.

vSphere Web Client

1. Log on to vSphere Web Client.
2. Select vCenter from the Home menu. Select Hosts and Clusters under the Inventory Trees.
3. Expand the tree in the left pane. Click the ESX host to disable the warning for (should have a yellow exclamation mark), and click Manage.
4. Click Settings, then Advanced System Settings.
5. Locate the parameter UserVars.SuppressShellWarning.
   Click the pencil icon to edit.
   Set its value to 1, then click OK.

Command line (using vim-cmd)

1. Connect to the ESX host to disable the warning for. Use the root account, connecting through SSH.
2. Run the following command to disable the warning:

   vim-cmd hostsvc/advopt/update UserVars.SuppressShellWarning long 1

Undo changes

Follow the steps above, depending on the method you'll use. Instead of setting the value to 1, setting the value to 0 will re-enable the warning for the particular ESX host.