Usually for a server application you want a fixed allocation of memory.
Set -Xms and -Xmx to the same value. It shouldn't be all of the system
memory - you will want some for the operating system and file cache. If
you have variable heap sizes with maximum near physical memory size,
then when all the applications are hit at once the machine will swap badly.

Don't start opening desktop applications on the server. Small
administrative programs should just take physical memory away from the
file cache. Probably the best move is to buy boatloads of RAM.

Tom Hawtin