One of my Xserves has a amber flashing LED. I've pointed out the LED in question in the below image:

What does this indicate and what do I need to do about it?
One of my Xserves has a amber flashing LED. I've pointed out the LED in question in the below image:

What does this indicate and what do I need to do about it?
Extracted from the Xserve User Guide:
System identifier button and light: The yellow system identifier light flashes if a problem is detected. You can also turn it on or off manually by pressing the button, or turn it on remotely using Server Monitor. This indicator is useful for locating a particular unit in a rack with more than one Xserve. A second system identifier button and light are on the back of the Xserve.
So, a yellow light indicates an error. You should check the Server Monitor or the /var/log tab in the Applications/Utilites/Console application.
Just so you know, this Button/Light thing, are on both sides of the Xserve.
I just found the answer to this. From the Trouble shooting manual:

As the LED flashed but did not alternate between flashing and off, I didn't have an alarm condition. Just pressing the light solved the issue.
I'd have deleted the question, but thought the solution (even if trivial) might save someone else down the line some trouble.