vSphere 5.x Tip To Toe: VSA Appliance root access! Why?
Sometimes you get odd requests from customers but usually they have a valid argument, in this case a customer had an intelligent UPS which performs a soft shutdown of the virtual machines in case of power failure and the batteries reach a minimum percentage of life.
So my first attempt to troubleshoot this was to create a script to shutdown the VSA cluster and then appliances gradually but this attempt was a fail because you can’t shutdown any of the VSA appliances normally, it must be killed in the script using esxcli (killing it did mess things up and I ended up with an appliance that is not seen by the VSA cluster).
And if you notice normally, if you right-click on any of the VSA appliances the shutdown/poweroff selection is dimmed and you’re only allowed to perform a reset, on the other hand these selections do not get dimmed when you connect directly to an ESXi host via the root credentials, but again the UPS application can’t talk to an ESXi directly it must be always done via utilizing the API’s of the vCenter server.
Finally, I thought it was not possible but then after I researched a little but I found out this article (http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2034830) which explains how to gain root access to a VSA appliance.
By default SSH is disabled, but after you put debugon SSH gets enabled automatically and I was able to upload the UPS agent for Linux on the VSA appliance which made it possible for the UPS to shutdown this virtual machine on the assumption that its a Linux system and not a virtual machine ^_^.
I hope haven’t been too much talkative but I’m sure that some of you might face such a case :)}.