(1) If I need a scalable storage service, what are the tradeoffs in using a scalable disk service like FAB as the foundation vs. purpose-built scalable file system, like GFS or Ceph? (2) Does FAB depend on synchronized clocks? What happens if the clocks on the bricks are skewed, i.e., the clocks on some bricks run faster than others? Does clock skew break FAB?