An apparatus, system, and process are disclosed for maintaining data in an
electronic storage array during multiple, concurrent drive failures. A
first drive failure is recognized and the storage system controller
subsequently enters a first operating mode. The storage system controller
then recognizes a second drive failure and enters a second operating
mode, which is different from the first operating mode, in response to
the second drive failure. The second operating mode allows the storage
system controller and a recovery module to access the data of the second
failed drive in a controlled manner in order to attempt to recover the
data on the first failed drive. Also, a pinned data module may allow
write data to be written to a pinned data drive, instead of a failed
drive, while the storage system controller is operating in the second
operating mode.