An integrated circuit implementing a storage-shelf router used alone, or
in combination with other storage-shelf routers, and in combination with
path controller cards, to interconnect the disks within a storage shelf
or disk array to a high-bandwidth communications medium through which
data is exchanged between the individual disk drives of the storage shelf
and a disk-array controller. In various embodiments, the present
invention provides virtual disk formatting by a storage shelf router and
the storage shelf in which the storage-shelf is included, to external
computing entities, such as disk-array controllers and host computers. By
providing virtual disk formatting, a storage-shelf router can provide to
a disk-array controller, and other external computing entities, the
disk-formatting convention expected by the disk-array controller, even
though disk drives and other storage systems that do not conform to the
expected formatting conventions may be included in the storage shelf and
interconnected to a disk-array controller and other external processing
entities via an interface provided by a storage-shelf router. Virtual
disk formatting, in addition, allows a storage-shelf router to format a
disk drive differently from the disk formatting expected by external
computing entities, so that the storage-shelf router can transparently
include additional information into disk sectors, such as additional
error detection and error-correction information.