Writing and reading data in a data storage format
AssigneeHewlett-Packard Development Company, L.P.
InventorJonathan Peter Buckingham
Life of this patent
Estimating the term…
Abstract
Data are written to plural parallel data tracks of a data storage medium by arranging a data stream into plural streams of data sets. Each stream of data sets is allocated to a corresponding respective group of parallel data tracks. A plurality of the data sets are written to the plural data track groups, such that in each data stream, each data set commences at substantially the same position along a length of the linear data storage medium, as a data set of another of the streams.
Claims29
A method of writing data to a data storage medium, said method comprising:
- arranging data into a plurality of streams of data sets;
- allocating each said stream of data sets to a corresponding respective group of a plurality of data tracks;
- and
- writing said data sets to said data track groups of said data storage medium, such that in each said data stream, each data set commences at a substantially same position along a length of said data storage medium, as a data set in each other said stream of data sets.
A write channel capable of writing a plurality of physical data tracks in parallel along a data storage medium, said write channel comprising:
- an interface for interfacing with a data source for receiving data into said write channel;
- a logical formatter for logically formatting said received data into a plurality of streams of data sets;
- a first physical formatter for formatting a first said stream of data sets for writing each said data set of said first stream across a first group of data tracks on said data storage medium;
- a second physical formatter for formatting a second said stream of data sets for writing each said data set of said second stream across a second group of data tracks of said data storage medium, said first and second groups of data tracks being positioned in parallel with each other.
A method of writing a plurality of data streams in parallel, said method comprising:
- receiving a host data stream;
- arranging said host data stream into a plurality of streams of data sets;
- allocating said streams of data sets to corresponding respective groups of data tracks;
- and
- writing said streams of data sets in parallel to said groups of data tracks, wherein a plurality of said data sets of different said streams of data sets commence at substantially a same position as each other along said data storage medium.
A method of reading data from a linear data storage medium, said method comprising:
- reading a plurality of streams of data sets recorded across a corresponding respective plurality of groups of physical data tracks in which individual data sets on different said groups of physical data tracks start in parallel at the same position as each other, wherein said data sets have been recorded with additional space occupied by padding bytes;
- and
- reconstituting said plurality of streams of data sets as a single stream of a plurality of data sets, by ignoring said padding data.
A read channel for reading a data stream comprising a plurality of data sets and padding data, said read channel comprising:
- a read head for reading in parallel a plurality of streams of data sets from a plurality of groups of physical data tracks on a data storage medium, said read head capable of reading in parallel a plurality of data sets written on different said groups of tracks which start and finish in parallel at equivalent said physical start and finish positions as each other, including any additional space occupied by padding bytes, and including any additional space occupied by data re-writes and
- a read formatter for formatting said plurality of read data sets;
- wherein said formatter is arranged to remove said padding, and is arranged to reconstitute said plurality of data sets as a single data stream.
A write formatter for writing data to a data storage medium, said write formatter comprising:
- a data stream multiplexer for arranging data into a plurality of streams of data sets;
- a plurality of physical formatters for allocating said streams of data sets to corresponding respective groups of parallel data tracks, such that in each said stream, of data sets each data set is timed to be available for commencing writing at substantially the same position along a length of a data storage medium, as each other said data set of each other said stream of data sets.
A write formatter capable of formatting data into a plurality of physical data track groups, said write formatter comprising:
- an interface for interfacing with a data source for receiving data to be formatted;
- a logical formatter for logically formatting said received data into a plurality of data sets;
- a first physical formatter for formatting said data sets into a first stream of data sets for allocation to a first group of data tracks;
- and
- a second physical formatter for formatting said data sets into a second stream of data sets for allocation to a second group of data tracks.
A data processing device for formatting data into a plurality of physical data track groups, said data processing device comprising:
- means for interfacing with a data source for receiving data to be formatted;
- means for logically formatting said received data into a plurality of data sets;
- a first means for formatting said data sets into a first stream of data sets corresponding to a first group of data tracks;
- and
- a second means for formatting said data sets into a second stream of data sets corresponding to a second group of data tracks.
A data processing device for writing a plurality of data streams in parallel, said device comprising:
- means for receiving a host data stream;
- means for arranging said host data stream into a plurality of data streams, each said data stream comprising a stream of data sets;
- means for allocating said data streams to corresponding respective groups of data tracks;
- and
- means for writing said data streams in parallel in said groups of data tracks, wherein said write means is configured for writing such that a plurality of data sets commence at substantially a same position as each other along said data storage medium.
A read formatter for formatting a plurality of data streams read in parallel from a plurality of physical data tracks of a data storage medium, said read formatter comprising:
- means for receiving in parallel a plurality of data streams each comprising a plurality of data sets;
- means for removing padding data from said read data streams;
- and
- means for reconstituting said plurality of data streams as a single data stream comprising a plurality of said data sets.
A write controller for writing data to a plurality of physical tracks of a data storage medium, said controller comprising:
- at least one logical formatter operable for logically formatting data;
- a plurality of physical formatters, each operable for physically formatting data into a plurality of physically formatted parallel data streams suitable for writing to a corresponding respective plurality of groups of parallel physical tracks each data stream comprising a stream of data sets;
- wherein, in operation, if a said data set of a first said data stream encounters a greater number of write re-tries different to an amount of write re-tries encountered by at least one other said data set of at least one other data stream, said controller is operable for inserting a plurality of padding bytes into whichever of said data streams encounters a lesser number of re-write bytes, such that all of said parallel written data sets, including said padding bytes, terminate at a substantially equivalent physical position as each other.
Dependencies are inferred from the claim text.