In one embodiment, a first storage device and a second storage device form
a mirror. When the first storage device loses synchronization with the
second storage device, data present in the second storage device but not
in the first storage device are identified. The identified data are then
copied to the first storage device. In one embodiment, a method of
rebuilding data in a storage device includes the act of replacing a
failed storage device with a replacement storage device. Up-to-date data
for the failed storage device, which may be stored in a corresponding
mirror, may then be copied to the replacement storage device. Thereafter,
the replacement storage device and any other storage devices that have
lost synchronization with their mirror are resynchronized.