Patent ID: 7240242
Filing Date: 2007-07-03
Classification: G06F

Abstract:
1. A method to convert data payloads from a first sector format to a second sector format, comprising the steps of: providing an information storage and retrieval system which includes information comprising a plurality of first sectors written in a first sector format; a device controller; a data storage device, wherein said data storage device comprises an information storage medium comprising a plurality of second sectors each comprising a second sector format; a sector format conversion device comprising a data queue, a buffer, and nonvolatile memory; a communication link interconnecting said sector format conversion device and said device controller; wherein said sector format conversion devices is interconnected with said data storage device; providing a plurality of Inflight Indicators, wherein each Inflight Indicator comprises either a first value or a second value, and wherein the (i)th Inflight Indicator is associated with the (i)th converted DMA data payload; setting a power failure warning time interval; forming a plurality of DMA data payloads each comprising a plurality of first sectors, wherein each of said plurality of DMA data payloads comprises a beginning logical block address and an ending logical block address; sending to said sector format conversion device one or more of said DMA data payloads; overlaying by said sector format conversion device the (i)th DMA data payload onto part or all of a plurality of second sectors to form the (i)th converted DMA data payload; enqueuing said (i)th converted DMA data payload in said data queue; transmitting said (i)th converted DMA data payload to said data storage device; setting the (i)th Inflight Indicator to a second value when transmitting said (i)th converted DMA data payload to said data storage device; writing said (i)th converted DMA data payload to said information storage medium; generating the (i)th Write Complete Signal by said data storage device after writing said (i)th converted DMA data payload to said information storage medium; resetting the (i)th Inflight Indicator to said first value upon receiving the (i)th Write Complete Signal; determining if a power failure warning has been received; operative if a power failure warning is received: starting said power failure warning time interval; providing one or more converted DMA data payloads from said queue to said data storage device during said power failure warning time interval, wherein said queue includes (P) enqueued converted DMA data payloads; determining if said power failure warning time interval is expired; operative if said power failure warning time interval is expired; determining if the (j)th converted DMA data payload has been written to said information storage medium, wherein (j) is greater than or equal to 1 and less than or equal to (P); operative if the (j)th converted DMA data payload has not been written to said information storage medium at the expiration of said power failure warning time interval, saving the (j)th converted DMA data payload in nonvolatile memory; losing utility power to said information storage and retrieval system; restoring utility power to said information storage and retrieval system; determining that (Q) converted DMA payloads remained In Flight at the time of utility power loss; retrieving from said nonvolatile memory each converted DMA data payload that was not written to said information storage medium prior to loss of utility power; and providing to said data storage device each converted DMA data payload that was not written to said information storage medium prior to loss of utility power.