05586291 is referenced by 255 patents and cites 27 patents.

A disk storage subsystem includes both volatile and non-volatile portions of memory. In response to a write command from a host computer, the controller allocates a predetermined number of memory blocks in the non-volatile cache memory and allocates a corresponding number of blocks in the volatile memory. Host supplied write data is then stored in the allocated non-volatile memory blocks. The data may also be mirrored in additional non-volatile memory. Immediately thereafter the subsystem sends an acknowledge signal to the host. The subsystem then performs a DMA operation to copy the write-data from the non-volatile memory blocks to the volatile memory blocks. The write-data is then stored on a disk drive at which point the non-volatile memory may be de-allocated. Subsequent reads of the given data may be read from the volatile memory, reducing disk access time. In the event of a power failure, data stored in the non-volatile memory but not yet written to disk is preserved. In the event of a disk controller failure, the non-volatile memory modules may be transferred to a functioning disk controller for recovery.

Title
Disk controller with volatile and non-volatile cache memories
Application Number
8/363298
Publication Number
5586291
Application Date
December 23, 1994
Publication Date
December 17, 1996
Inventor
James M McGillis
Franklin
MA, US
Jeffrey M Lasker
Marlboro
MA, US
Agent
Weingarten Schurgin Gagnebin & Hayes
Assignee
EMC Corporation
MA, US
IPC
G06F 13/00
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