I just finished my almost last assignment for my current university before the holidays and before I got to Trinity College. It's an essay for the software architecture course I took. I thought I'd put it online for those interested. It's not a masterpiece, but it should do for the credits I get for it (it's only 30% of the grade). In this essay, runtime quality attributes of distributed storage systems are discussed. These quality attributes are scalability, security, robustness and performance. For three different distributed storage systems (GoogleFS, DISP and Gnutella), the architecture and fulfilment of these quality attributes are looked at and evaluated.