Patent ID: 7231546
Filing Date: 2007-06-12
Classification: G06F

Abstract:
1. A method to overlay (n) first sectors onto (m) second sectors using a data queue, 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 (j)th overlain second sector; setting a power failure warning time interval; providing (N) contiguous first sectors to said sector format conversion device, wherein said (N) first sectors include a beginning first sector and a first number of bytes; determining that (M) contiguous second sectors comprise at least said first number of bytes, wherein said (M) contiguous sectors comprise a beginning second sector and an ending second sector; overlaying by said sector format conversion device the (i)th first sector onto part or all of the (j)th pre-existing second sector to form the (j)th overlain second sector, wherein (i) is greater than or equal to (N), and wherein (j) is greater than or equal to 1 and less than or equal to (M); enqueuing said (j)th overlain second sector in said data queue; transmitting said (j)th overlain second sector to said data storage device; setting the (j)th Inflight Indicator to a second value when transmitting said (i)th overlain second sector to said data storage device; writing said (j)th overlain second sector to said information storage medium; generating a (j)th Write Complete Signal by said data storage device after writing said (j)th overlain second sector to said information storage medium; resetting the (j)th Inflight Indicator to said first value upon receiving the (j)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; monitoring the status of each Inflight overlain second sector; determining if said power failure warning time interval is expired; operative if said power failure warning time interval is expired: saving to nonvolatile memory each overlain second sector for which a write complete signal was not received prior to the expiration of said power failure warning time interval; losing utility power to said information storage and retrieval system; restoring utility power to said information storage and retrieval system; retrieving from nonvolatile memory each overlain second sector for which a write complete signal was not received prior to the expiration of said power failure warning time interval; and providing to said data storage device each overlain second sector for which a write complete signal was not received prior to the expiration of said power failure warning time interval; writing to media each overlain second sector for which a write complete signal was not received prior to the expiration of said power failure warning time interval.