I recently had to expand the RAM of a web server, specifically, Dynamic cloud 1&1, I had an initial configuration of 4GB and 8GB have expanded.
The process is really easy from the panel of 1&1 (“Hardware Configuration”) and after a couple of hours with the server down to 1&1 Perform the requested changes with the server has started the new 8Gb memory hired.
My surprise 
has been to access the server Plesk panel (version 10.3.1) When we review in the window “Server Status” I've seen that still appeared the initial contract 4Gb:
After asking my friend David (thanks!) and the support 1&1 (I'm still waiting for reply) I found the solution in diving final Plesk Panel forums.
Just execute the following statement from the root of our server accessed by SSH:
/usr/local/psa/bin/sw-engine-pleskrun /usr/local/psa/admin/plib/scripts/setup-health-monitor.php
Now our Plesk Panel will know we have updated our hardware to 8GB and you can see the new ONFIGURATION in the same previous window “Server Status”:
Until next time!.