Storage Technology Corporation

Sun Microsystems, Inc.

Oracle International Corporation

Oracle America, Inc.

Richard A Gill

Keith Gary Boyer

Roger D Hayes

Benjamin Joseph Baron

Steven Gregory Trabert

Robert O Wyman

James William Wolf

Randy Allen Fout

Christopher P Zook

Mark Hennecken

Jin Lu

Bradley Edwin Whitney

Chad Alber

Howard H Rather

Thomas H Gohl

Erich R Oetting

James Wolf

A method for validating media and drives. The method includes receiving a validation request for a data storage tape in a library and, with the tape loaded into a predefined gold drive in the tape library, performing a statistical analysis on the tape to determine an operating parameter such as a measure of read margin for the tape in the predefined gold drive. The method includes validating the tape when the operating parameter compares favorably with a threshold limit defined for the operating parameter for the tape library. The method includes, when the operating parameter fails to compare well with the threshold limit, running a performance test on a drive qualified tape from the library loaded into the predefined gold drive and, when the drive qualified tape passes the test, identifying the tape as degraded. The method includes, when the drive qualified tape fails the test, re-qualifying the gold drive.

Media and drive validation in tape libraries

An LDPC coding system includes a number of LDPC encoders and a number of LDPC decoders. The number of encoders/decoders is between one and one fewer than the total number of tracks on the high density tape are provided. The LDPC encoders are operable to break data from an incoming data sector into the data blocks to be written to the high density tape. The LDPC decoders are operable to assemble the data blocks into data sectors.

High density tape drive multi-channel low density parity check coding control

A method is disclosed. The method includes performing a first read operation at a tape drive, determining if a minimum number of data bytes have been recovered in the first read operation to perform error correcting codes (ECC), performing a second read operation if the minimum number of data bytes to perform ECC have not been recovered, determining if a minimum number of data bytes have been recovered in the second read operation to perform ECC, combining the recovered data bytes from the first read operation and the second read operation to form combined recovered data bytes, determining if a minimum number of data bytes are included in the combined recovered data bytes to perform ECC and performing ECC if the minimum number of data bytes are included in the combined recovered data bytes.

Method for recovering data in a tape drive system

A method for dynamically adjusting read margin and write margin in a tape drive system to recover data is disclosed. The method includes the operations of monitoring a write driver to determine if a change in rewrite activity to a medium has changed and adjusting a percentage of error correcting code (ECC) capability to be used for write errors if the rewrite activity has changed. An apparatus including a tape medium and a read/write controller for performing the method is also disclosed. In one embodiment, the percentage of ECC is decreased if the rewrite activity to the medium increases.

Write margin adjustment mechanism in a tape drive system

A method for contiguously appending data onto media in a tape drive system is disclosed. In one embodiment, the method includes reading existing data recorded on a media, determining an append point on the media, and contiguously appending new data on the media starting at the append point such that any end pad is eliminated and no intermediate pads are resulted. Other embodiments are also disclosed.

Method and system for contiguously appending data onto media in a tape drive system

A method for increasing recording format reliability in a tape drive system is disclosed. In one embodiment, the method includes identifying a default media information region (MIR) on a media, wherein the default MIR includes MIR information divided into segments, reading the MIR information, rotating the MIR information into a first rotation MIR information by rotating the segments by one segment; and writing the first rotation MIR information into a first MIR on the media. Other embodiments are also disclosed.

Method and system for increasing recording format reliability for limited media space in a tape drive system

In one embodiment, a method and apparatus for isolating marginal recording to media or recording apparatus is disclosed. The method includes generating an experience metric from an interaction between a media mounted in a drive, updating one or more metrics for each of the media and the drive based on the experience metric and one or more prior metrics of the media and the drive, storing the one or more updated metrics to the associated media and drive, and utilizing the one or more updated metrics to predict performance trends of the media and the drive for preventative maintenance purposes. Other embodiments are also disclosed.

Mechanism for isolating marginal recording to media or recording apparatus

A method for writing data in a tape drive is provided by the present invention. The present invention provides a method for writing data in a tape drive. The invention include allocating a blank area for transpose writing on a magnetic tap and then writing a first group of data sets on the magnetic tape adjacent to the blank area. The tape drive maintains full operating speed during intervals between writing successive data sets, resulting in spaces between the data sets. At a specified interval, the drive repositions the tape writes a transposed data block to the allocated blank area, wherein the transposed data block contains the same content as the first group of data sets. A new blank area for transpose writing is then allocated adjacent to the recently transposed data block.

Performance enhancement for tape write immediate operations

In one embodiment, a method and apparatus for minimizing unload times in a tape drive system is disclosed. The method includes: writing to a tape in serpentine format; reaching a comparison point on the tape, wherein at the comparison point an actual capacity is compared to an expected capacity; utilizing the comparison at the comparison point to estimate a distance from the comparison point until a guaranteed capacity for the tape is reached; and determining a turn-around point on the tape based on the estimated distance, wherein at the turn-around point a tape drive writing to the tape to stop writing in a first direction and then continue writing in a second direction opposite from the first direction and towards a physical beginning of the tape. Other embodiments are also disclosed.

Mechanism for minimizing unload times in a tape drive system

A drive and method of identifying write velocity during reading are provided. When a track is being read, the data signal is processed prior to determining the data stream to identify the velocity with which the track data were written. The read channel is adjusted based on the identified velocity to compensate for write channel transfer function variation.

Write velocity identification

A tape drive for use with magnetic tapes includes a housing for receiving a magnetic tape having multiple parallel tracks, and a tape head for reading and writing the parallel tracks of the magnetic tape. A plurality of partial response maximum likelihood (PRML) equalization/detection channels are provided for processing the data signals to determine the data stream for each data signal. The plurality of PRML equalization/detection channels includes at least one PRML equalization/detection channel pre-assigned to each track. The plurality of PRML equalization/detection channels further includes at least one floating PRML equalization/detection channel dynamically assignable on an as-needed basis. The invention also contemplates an ASIC, a generic drive, and a PRML method.

Dynamically allocated parallel equalization and detection of a PRML read channel in a multi-channel drive

A method and system are provided for dynamically shortening a number of error correction codewords to correspond to an amount of user data to be recorded on a recording medium. The system and method determine in advance that the number of bytes of user data will only fill a portion of a codeword matrix, and automatically shortens the size of ECC word segments to match the actual user data fill. This allows an ECC interleave to be completed with only a partial fill of the matrix, thereby reducing the required number of recording passes and associated processing time.

Dynamic error correction code shortening

A tape drive and method of identifying write velocity during reading are provided. When a track is being read, a lead-in code of the data signal is processed prior to determining the data stream. The lead-in code identifies the velocity with which the track data were written. The equalization/detection channel is adjusted based on the identified velocity to compensate for write channel transfer function variation. The lead-in code is coded in a way that is reasonably immune to write channel transfer function variation such that the lead-in code is comprehended prior to adjusting the equalization/detection channel.

Write velocity identification in a PRML system

An asynchronous method for locating individual blocks of data in a tape drive, without having to read the blocks of data is provided. The invention comprises placing an ID mark adjacent to the data blocks and inter-block gaps on the tape. The ID mark contains a small amount of information about the next respective data block on the tape. The ID mark is encoded such that the same detection mechanism that detects the inter-block gap can also retrieve the ID mark information, without having to process the entire block of data associated with a particular ID mark. The ID mark is symmetrical such that it can be detected and decoded in the forward and backward direction, allowing the tape drive to find a desired block of data by searching either forward or backward, even when the magnetic tape uses a unidirectional data format.

Pre-block ID mark for multi-directional block location when using a unidirectional coding format

A method, apparatus, and computer instructions for writing data to a magnetic media. A first frequency is written on a first track on the magnetic media on a first track width. A second frequency is written on the first track in which a combination of the first frequency and the second frequency encodes a bit of data on the first track. An erase pattern is created on a second track on the magnetic media, the second track being adjacent to the first track in which the bit of data on the first track is readable by a tape drive system having a second track width wider than the track width of the first track.

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Arvada, CO, United States of America

Richard A Gill