While checking out the PlanetV12n feed, I noticed a new video from David Davis about the new vSphere 4.1 Tech Support Mode. In the short video, David goes over the new method of enabling "hidden" unsupported Busybox Console, also known as Tech Support Mode. In the past, you had to be on the console of your ESXi host, type ALT+F1, and then "unsupported" to gain access. Once in, to enable remote SSH access or Remote Tech Support Mode, you had to edit /etc/inetd.conf and restart inetd service. This was pretty tedious if you needed access for a short period of time. In the video, David goes over the new method showing how it can be done using the DCUI and the old method is no longer required.
What surprised me after watching the video was that he did not mention the other method of enabling and disabling Tech Support Mode both local and remote. One issue I had with past releases of ESXi is that you could restart some services such as ntp or vmware-vpxa via the vSphere API, but others were just not available. In vSphere 4.1, VMware introduces a few new services around their Likewise Active Directory integration but also includes controlling both local and remote Tech Support Mode as well as DCUI itself.
These services can be enabled and disabled using the vSphere Client, here is a screenshot:
If you needed to perform this operation against one or two host, it is not that big of a deal. Though if you needed to enable remote Tech Support Mode (SSH access) across few dozen hosts, then can still be tedious. Luckily I wrote a script (hostServiceMangement.pl) last year that allowed you to enable and disable supported services using the vSphere API. Without any modifications, it supports vSphere 4.1 and can take advantage of the new services that are available for control.
Here is an example of listing the services on an ESXi 4.1 host:
The script can be executed on a host that has vCLI 4.1 installed or on vMA 4.1 and can bulk update a list of ESX/ESXi host or individual host. For more details, please check out the documentation for hostServiceManagement.pl.