An apparatus and method for accessing a data item from a storage system
having a plurality of data storage devices are disclosed. I/O operation
requests are submitted to multiple data storage devices for each data
item to be accessed. The I/O operation requests are issued to copies of
the data items that reside on a plurality of data storage devices. More
I/O operation requests are submitted than the number of data items that
are to be accessed, written, or updated.