A bi-directional reflective memory channel between a pair of storage controllers
is used to maintain a mirrored copy of each storage controller's native buffer
contents within the buffer of the other storage controller. To maintain such mirrored
copies, buffer write operations that fall within a reflective memory segment of
one storage controller are automatically reflected across this channel to the other
storage controller for execution, and vice versa. The write operations are preferably
transmitted across the reflective memory channel using a protocol that provides
for error checking, acknowledgements, and retransmissions. This protocol is preferably
implemented entirely in automated circuitry, so that the mirrored copies are maintained
without any CPU intervention during error-free operation. When a failover occurs,
the surviving storage controller uses the mirrored copy of the failed storage controller's
native buffer contents to assume control over the failed storage controller's disk drives.