Logical HDMI display reconnection I have a Mac mini server with Yosemite, and I plugged a VGA Display using a VGA/HDMI adapter.

The issue is, when I shut down or restart the server, the display is not recognized, then I need to go to unplug and plug again, and server now recognizes the display.

I need to know how to make a logical "reconnection" for the adapter. 

For example on Windows I use a devcom application to enable or disable the devices. 

I was reading that the possible solution is using a kextunload command on terminal.

I don't know which kextfile I need to "unload" for the HDMI adapter.

On terminal:

/System/Library/Extensions/

kextunload exampleflile.kext

kextload examplefile.kext

Anybody have an idea about my issue? Another way to solve it?

Thanks in advance

Greetings from Mexico.
You most likely need an active HDMI to VGA adapter.  There is a bunch of signaling conversion that goes on with an adapter, especially when it goes from digital (HDMI) to analog (VGA).  An active adapter will reformat the signals so it's a true VGA signal rather than just supply the correct pin outs.

Take a look at this answer, Passive vs. Active adapters - I talk about the difference and why it's important.