The system says shows that I have used up all my ram, should I be concerned?
Unix (Linux/FreeBSD) boxes can often cause confusion with memory usage. If you run "top", it will normally show you that about 98% of the memory has been used up. This is actually normal and no, you probably have not run out of ram. Unix is always doing it's own internal house keeping with the system, thus will use up the available memory to do so. If a real program is started up and it needs that memory, the house keeping tasks are instantly dropped and that memory is freed up for the program that needs it.
You only have to be concerned with memory usage once your swap memory starts to grow. If the swap usage is less than about 10 meg and isn't moving or growing, then you're still in the green. Only once you see your swap memory usage starting to climb do you have to worry. If that happens, then you either need more ram, or else one of your programs is chewing up memory quickly due to heavy system load (eg, volumes of mysql queries) or possibly program memory leaks. Sometimes restarting apache and mysql can reduce the amount of memory used, but it will usually grow back up to where it was over time.
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