Ping-pong state machine for storage-device array

In one embodiment, an apparatus for reading from a physical storage-device array including a plurality of storage devices. The physical storage-device array has a plurality of sector levels, each sector level containing one sector on each storage device in the array at corresponding addresses on across the storage devices. The apparatus includes: (1) a memory adapted to store two or more profiles, each profile defining (i) a virtual array associated with a selected set of the storage devices and (ii) one or more parameters used for accessing information from the virtual array; (2) a buffer (i) having a first portion and a second portion and (ii) coupled to receive data from the storage devices; and (3) a state machine (i) coupled to the buffer and the memory and (ii) adapted to generate two or more successive pairs of instructions. The first instruction of each pair of instructions (i) is based on one or more parameters of a first profile and (ii) is an instruction to read, into the first portion of the buffer, one sector of data from each storage device of a first virtual array; and the second instruction of each pair of instructions (i) is based on one or more parameters of a second profile and (ii) is an instruction to read, into the second portion of the buffer, one sector of data from each storage device of a second virtual array.