Banding can be prevented and image-quality degradation can be reduced. The file system provides a virtualization system that aggregates physical storage of a set of disks or portions of disks into a pool of blocks that can be dynamically allocated to form a vdisk. The technique distributes the assignment of disks to parity groups among the combined super-stripe array such that all disks contain the same amount of data or parity information. One or more vanes is provided that create an annular vortex within the filtration housing interior. A copy of the configuration data is transferred to shadow registers in the shadow integrated circuit.