International Business Machines Corporation

Scott Milton Fry

Pamela Ruth Nylander-Hill

Richard Anthony Ripberger

James Mitchell Karp

Takashi Katagiri

Paul Merril Greco

Scott A Jackson

Erika Dawson

Gavin Stuart Johnson

Joel Kenneth Lyman

Jon Arthur Lynds

Steven Douglas Johnson

Neil H MacLean, Jr

Steven Bennett Wilson

Cory G Smith

Edwin C Dunn

Harry O Hempy

Richard P Reynolds

Eiji Ogura

Reed Alan Hancock

Bruce E Kittinger

Hiroshi Itagaki

Ernest Stewart Gale

Robert Beverley Basham

Kenji Nakamura

Hirokazu Nakayama

David Lee Swanson

Alex Chliwnyj

Jerry Wayne Pence

Wayne Erwin Rhoten

Sushama M Paranjape

Warren B Harding

Vincent K Allen

Charles R Kirkpatrick

Yutaka Ooishi

Habib M Torab

Robert G Long

Yutaka Oishi

Kirby Grant Dahman

Kevin Dale Butt

Duke Andy Lee

Will A Wright

John James Gniewek

David C Graves

Mark Edward Hill

Michael M Lee

David C Cole

Phuoc D Phan

In one embodiment, a product includes a magnetic medium having written thereon data in a data track. The data includes encrypted data written over unencrypted data. An indicator of a physical position on the magnetic medium that corresponds to an end of the encrypted data is stored on the product. A product according to another embodiment includes a magnetic medium having written thereon data in a data track. The data includes encrypted data written over unencrypted data. A portion of the unencrypted data is located before the encrypted data on the medium. An indicator of a physical position on the magnetic medium that corresponds to a beginning of the encrypted data is stored on the product.

Monitoring of residual encrypted data to improve erase performance on a magnetic medium

A method for dynamically changing a buffer threshold in a tape drive, according to another embodiment, includes monitoring a history of sizes of data transactions between sync commands, the data transactions being from a host to a tape drive, determining that a next sync command is expected to be received relatively sooner or relatively later based on the history of data size transactions, writing buffered data to a magnetic recording tape in response to determining that the next sync command will be received relatively sooner, and increasing a buffer threshold for delaying writing to the magnetic recording tape in response to determining that the next sync command will be received relatively later. A computer program product according to one embodiment includes a computer readable storage medium having program code embodied therewith, the program code readable/executable by a processor to perform the foregoing method.

Dynamically changing a buffer flush threshold of a tape drive based on historical transaction size

According to one embodiment, a method for dynamically changing a buffer threshold in a tape drive includes determining that a drive buffer is emptied of data, calculating a write size indicating an amount of data from a transaction size left to be written to a tape prior to a next anticipated sync command, setting a buffer threshold that triggers a back hitch to a smaller value when the transaction size is less than a buffer size, setting the buffer threshold to the smaller value when an absolute difference between the transaction size and the write size is greater than or equal to the buffer size, and setting the buffer threshold to a larger value when the transaction size is not less than the buffer size and/or the absolute difference between the transaction size and the write size is less than the buffer size.

In one embodiment, a system includes a processor and logic integrated with and/or executable by the processor, the logic being configured to: determine a physical position on a magnetic medium that corresponds to an end of an encrypted data set; store an indicator of the physical position on the magnetic medium and/or a memory coupled thereto; and cause obscuring of an unencrypted data set positioned after the physical position without overwriting the encrypted data set. In another embodiment, a computer program product includes a computer readable storage medium and program instructions embodied therewith, the program instructions readable and/or executable by the processor to cause the processor to: read an indicator of a physical position on a magnetic medium that corresponds to an end of an encrypted data set; and cause obscuring of an unencrypted data set positioned after the physical position without overwriting the encrypted data set.

A method, system and computer-usable medium are disclosed for reordering User Data Segment (UDS) lists to reduce seek times when accessing data stored on tape media. A host application sends a list of UDSs to a target tape drive and requests the tape drive to reorder the list to provide better performance. An ordered list of target User data Segments to retrieve from a target tape media is received. Information related to the location of each UDS on the target media is processed to determine its corresponding physical position on the tape media. The resulting physical positions are then processed to generate a reordered UDS list, where the order of the User Data Segments is reordered according to their physical location on the target tape media. The reordered list of User Data Segments is then used to perform seek, reposition and read operations to read User Data Segments from the tape media.

Method for reordering access to reduce total seek time on tape media

In one embodiment, a system includes a processor, logic in the processor and/or memory configured to determine a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, and logic configured to store an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto. In another embodiment, a method includes determining a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, storing an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto.

A system according to one embodiment includes a processor; logic in the processor and/or a memory configured to determine a furthest physical position on a magnetic medium that unobscured data has been written to; and logic configured to store an indicator of the furthest physical position on at least one of the magnetic medium and a memory coupled thereto. A system according to another embodiment includes a processor; logic in the processor and/or a memory configured to receive an instruction to obscure data on a magnetic medium; logic configured to read an indicator of a furthest physical position on the magnetic medium that unobscured data has been written to; and logic configured to cause obscuring of the unobscured data on the magnetic medium, and terminating the obscuring upon reaching the physical position in the indicator.

Monitoring of extent of writing of unobscured data to improve erase performance on a magnetic medium

A method in one embodiment includes receiving a command to perform at least one of a refresh operation and a verification operation on a media cartridge having a tape wrapped around a spool; mounting the media cartridge in a tape drive; starting execution of the refresh and/or verification operation; aborting execution of the refresh and/or verification operation upon occurrence of a predetermined event. A method in another embodiment includes receiving an instruction to perform a verification operation on a media cartridge having a tape wrapped around a spool; unwrapping at least some of the tape from the spool; after the unwrapping, wrapping at least some of the tape back onto the spool; during at least one of the unwrapping and wrapping, performing a verification operation; terminating execution of the verification operation when a drive error is detected; outputting an indication of a media error when a media error is encountered.

Cartridge refresh and verify

A method according to one embodiment includes monitoring a data transfer operation for detecting temporary errors; determining whether an error burst has occurred based on the monitoring; if an error burst has occurred, altering a condition of the data transfer operation; monitoring the data transfer operation having the altered condition for detecting temporary errors; determining whether another error burst has occurred based on the monitoring of the data transfer operation having the altered condition; and if another error burst has occurred, altering another condition of the data transfer operation. Additional systems and methods are also presented.

Error burst detection and amelioration

A method according to one embodiment includes monitoring a data transfer operation for detecting temporary errors; determining whether an error burst has occurred based on the monitoring; if an error burst has occurred, altering a condition of the data transfer operation; monitoring the data transfer operation having the altered condition for detecting temporary errors; determining whether another error burst has occurred based on the monitoring of the data transfer operation having the altered condition; and if another error burst has occurred; altering another condition of the data transfer operation. Additional systems and methods are also presented.

A method according to one embodiment includes: deciding to perform a refresh operation on a media cartridge having a tape wrapped around a spool; determining which drive of a plurality of drives is available to perform the refresh operation; causing the media cartridge to be mounted to the available drive; causing the drive to unwrap the tape from the spool of the media cartridge to about an end of the tape; and causing the drive to wrap the tape back onto the spool after the unwrapping, wherein at least some data on the tape is overwritten with new data, and a verification operation is performed using the new data.

A method according to one embodiment of the present invention includes receiving an instruction to perform a verification operation on a media cartridge having a tape wrapped around a spool; unwrapping at least some of the tape from the spool of the media cartridge; after the unwrapping, wrapping at least some of the tape back onto the spool; during at least one of the unwrapping and wrapping (and preferably both, and possibly over several cycles of unwrapping and wrapping), performing a verification operation; generating a quality metric based on the verification operation; and outputting the quality metric or derivative thereof, such as a pass or fail indication; an instruction to set a pass/fail flag; a number, score or graphic illustrating to a user a general quality of the tape, etc. Additional methods and systems are also presented.

A plurality of tape drives writes a plurality of indicators corresponding to a plurality of data units on a tape, wherein an indicator indicates which tape drive of the plurality of tape drives has written a corresponding data unit on the tape. Each of the plurality of tape drives generates an extent of read errors, in response to reading the plurality of data units written on the tape. The extent of read errors generated by each of the plurality of tape drives are aggregated at a computational device coupled to the plurality of tape drives. A determination is made at the computational device of a defective tape drive of the plurality of tape drives from the aggregated extent of read errors.

Detection of defective tape drive by aggregating read error statistics

An apparatus, system, and method are provided for developing failure prediction software for a storage system. The present invention allows a user to edit and revise a failure prediction algorithm that includes fuzzy logic rules. The failure prediction algorithm is generated in a human readable format and uses terms and operators familiar to experts in the field of storage systems. In addition, the present invention generates the machine-readable code necessary to implement or test a draft failure prediction algorithm. If the results of the failure prediction algorithm are unsatisfactory, the user may revise the failure prediction algorithm and re-run the tests until the results correspond to expected results. In addition, the present invention includes a performance monitor, processor, and determination module. The performance monitor gathers performance data for a storage system. The processor executes the failure prediction algorithm on the performance data to produce a result. The determination module selectively forecasts failure of one or more components of the storage system in response to the result.

Apparatus, system and method for developing failure prediction software

Growing community of inventors

Oro Valley, AZ, United States of America

Scott Milton Fry