hey guys, i've recently bought drive genius because - from what i can tell - my macbook air has significantly slowed down. and apparently my boot volume is a mess. please have a look: http://imgur.com/sRgi3.png you can only see part of the entire drive, but it's almost everywhere like this. would you suggest defragmenting? and if so, how could i go about that since i do not have an external drive? thank you for your help!