MAG locked up my system, is this common or bad?

So I was playing MAG last night, and it completely froze my system. I was wondering if this is something that happens with this game, or if it's something I should be worrying about in concern to the state of my ps3. I am planning on dusting out the inside of my system since I keep it on the floor which happens to be a rug. I also noticed that with MAG only, my system begins to get louder after about an hour of gameplay and starts to vibrate as if it is being strained (sorry, probably wrong wording). Since I couldn't get any response from the system I had to hard shutdown by pressing the off button, and it beeped a few times before going off. Hopefully someone here knows if this is something that just sort of happens with MAG (I heard this happened with the original Assassin's Creed) or if I should really be worrying.

It's rather common, it happened occasionally with me on both of my systems. Unless the system starts beeping by itself while the green light turns yellow then starts flashing red, then your system is fine.

Well it's good to see this is a relatively common thing with MAG, and not a problem with my system. My light didn't change color, so that's good. I was wondering, is there a way to backup my game saved files and dlc to an external hard drive just to be safe if anything ever does happen?

Yes there is, though I have not done it myself. You go to Settings, then I believe System Settings (not quite sure baout this) then Backup Data. You can Google it to get more accurate results, but make sure your external hard drive is in FAT32 format.