摘要:
A data writer is described comprising: a memory to store at least one amount of source data that is to be written to a data storage medium; a processor to arrange the source data into subsets and generate ECC data in respect of each subset, wherein the source data and the associated ECC data are to be written to a data storage medium via a plurality of individual data channels, and wherein the ECC data comprises at least a first degree of ECC protection having a first level of redundancy in respect of a first subset and a second degree of ECC protection having a second level of redundancy in respect of a second subset; a plurality of data writing elements, each to write data from an associated data channel, concurrently with the writing by the other data writing elements of data from respective data channels, to a data storage medium; and a controller, to control the writing by the data writing elements of the source data and the associated ECC data to the data storage medium.
摘要:
Data storage and retrieval methods and apparatus are provided for facilitating data de-duplication for serial-access storage media such as tape. During data storage, input data is divided into a succession of chunks and, for each chunk, a corresponding data item is written to the storage media. The data item comprises the chunk data itself where it is the first occurrence of that data, and otherwise comprises a chunk-data identifier identifying that chunk of subject data. To facilitate reconstruction of the original data on read-back from the storage media a cache (50) is used together with a database (35R), stored on the media, that includes for each duplicated chunk, the location of the corresponding chunk of subject data.
摘要:
Embodiments of methods and systems comprise identifying failing media and/or drives for a media library. Error data can be collected from media libraries. For each tape exhibiting an error rate of interest, a determination can be made whether the tape would still have been of interest had it not been loaded in certain drives. This information can be analyzed to identify failing drives or tapes.
摘要:
Writing data to magnetic tape is performed by receiving data from a host, establishing sub data sets, computing C1 and C2 ECC, forming Codeword Quad sets, writing a beginning Data Set Separator to a magnetic tape, writing a plurality of contiguous instances of the CQ Set to the magnetic tape and writing a closing DSS. The number of instances of each Codeword Pair is increased, thereby allowing the benefits of writing short tape records and improving reading reliability while reducing susceptibility to mis-tracking errors and large defects, and while reducing the negative impact on data reliability. Otherwise unused latency times are utilizing and therefore no performance penalty is incurred.
摘要:
Method and apparatus are provided for encoding and decoding rate-( s ( K +1))/( s ( K +1)+1) TCMTR( j,k,t,a ) codes, where s is the ECC symbol size in bits and K is the number of unencoded symbols that are interleaved with an ( s +1)-bit encoded block at the output of a rate- s /( s +1) encoder that encodes the r-th 5-bit symbol. K=m/s -1 where m=s(K +1) is the total number of bits to be encoded. Error propagation is reduced, thus allowing the ECC code to correct errors efficiently. Header error-rate is also reduced by eliminating occurrence of likely error events at the detector output. Although initially an RLL code may be designed for an ECC symbol size of s bits, the RLL encoding of the present invention may be used in conjunction with ECC schemes that utilize symbol sizes other than s bits.
摘要:
Enabling efficient navigation of a playlist of media files stored on a computer-readable medium. Aspects of the invention define a playlist structure to have one or more playlist units. Each playlist unit identifies one or more media files in the playlist and includes metadata for the media files. A consumer electronic device retrieves the playlist units and displays the metadata contained therein to a user to enable navigation of the playlist. Aspects of the invention reduce the memory requirements of the consumer electronic devices and reduce the quantity of disk seek operations needed for playlist navigation.