公开(公告)号：GB2495356B

公开(公告)日：2016-01-27

申请号：GB201212290

申请日：2012-07-11

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  JELITTO JENS ,  HUTCHINS ROBERT ALLEN

IPC: G11B5/584 ,  G11B20/10

Abstract: An apparatus according to one embodiment includes a digital correlator configured to compute a correlation signal between a sequence of samples of a readback servo signal and a reference waveform. A timing reference module is configured to provide a reference timing model comprising one or more interpolation instants to the digital correlator, wherein the correlation signal determined at each interpolation instant yields a detection metric for one data symbol. A correlation interpolator is configured to interpolate the correlation signal at the interpolation instants and compute a longitudinal position (LPOS) detection metric according to the interpolated correlation signal samples.

公开(公告)号：GB2525222A

公开(公告)日：2015-10-21

申请号：GB201406870

申请日：2014-04-16

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  JELITTO JENS ,  TSURUTA KAZUHIRO ,  FURRER SIMEON

IPC: G11B5/584

Abstract: An apparatus for operating a tape storage device comprises a tape skew estimation unit 4 for estimating a value related to a skew of a tape storage medium arranged in the tape storage device relative to a head module of the tape storage device. A servo pattern decoder 3 is configured to decode information encoded in a servo pattern written to one or more servo bands of the tape storage medium. The decoding is based on read-back signals RB1, RB2 of at least two servo readers of the tape storage device arranged for reading the servo pattern from the one or more servo bands and based on the estimated skew related value. The information can include longitudinal position (LPOS). The skew related value may be in the form of a time offset and the servo pattern decoder may include delay units 311, 312 for delaying a read back signal determined to be ahead in time before combining the read back signals. The read back signals may be weighted by a signal quality index (SDR).

公开(公告)号：GB2523059A

公开(公告)日：2015-08-12

申请号：GB201510786

申请日：2013-11-27

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  ENGELEN JOHAN B C ,  FURRER SIMEON ,  JELITTO JENS ,  LANTZ MARK ALFRED

IPC: G11B5/584

Abstract: A tape storage medium comprises at least one servo band (SB) along a longitudinal extension (x) of the tape storage medium (TP) for supporting to determine positional information. The servo band (SB) comprises a first servo subband (SB1) extending along the longitudinal extension (x) of the tape storage medium (1) and a second servo subband (SB2) extending along the longitudinal extension (x) of the tape storage medium (TP) next to the first servo subband (SB1). The first servo subband (SB1) comprises a frame servo pattern containing a set of servo frames (FR), wherein each servo frame (FR) of the set comprises a first burst (A) comprising at least two servo stripes (SP1) inclined at a first angle ( α) with respect to a direction orthogonal to the longitudinal extension (x) of the tape medium (TP), followed by a second burst (B) comprising at least two servo stripes (SP2) inclined at a second angle (β) with respect to the direction orthogonal to the longitudinal extension (x) of the tape medium (TP), which second angle (α) is different from the first angle (β). The second servo subband (SB2) contains a set of servo tracks (STx) extending along the longitudinal extension (x) of the tape storage medium (TP) and arranged next to each other, wherein each servo track (STx) of the set contains a servo pattern of magnetic transitions representing a waveform when being read, and wherein the waveforms of adjacent servo tracks (STx) are orthogonal to each other.

公开(公告)号：CA2636848C

公开(公告)日：2015-04-28

申请号：CA2636848

申请日：2007-01-10

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  ELEFTHERIOU EVANGELOS ,  JELITTO JENS ,  HUTCHINS ROBERT

IPC: G11B5/584

Abstract: A fully synchronous longitudinal position (LPOS) detection system is provided for improving the reliability of servo channels in tape systems. The system is based on the interpolation of the servo channel output signal, which is sampled by an analog-to-digital converter (ADC) at a fixed sampling rate, using a clock at a nominal frequency, so that interpolated signal samples are obtained at a predetermined fixed rate, independent of tape velocity. This predetermined fixed rate is defined in terms of samples per unit of length, as opposed to samples per unit of time, which is the measure of the ADC sampling rate. The resolution with which the servo channel signal is obtained at the interpolator output is thus determined by the step interpolation distance.

公开(公告)号：GB2517913A

公开(公告)日：2015-03-11

申请号：GB201315434

申请日：2013-08-30

Applicant: IBM

Inventor： JELITTO JENS ,  MITTELHOLZER THOMAS ,  SARAFIJANOVIC SLAVISA ,  SORNIOTTI ALESSANDRO ,  STANEK JAN

IPC: G06F17/30 ,  G06F3/06

Abstract: A method includes providing (S10), by at least one client, files to be stored on a remote server. The method then includes evaluating (S20) popularity of the files (e.g. the number of copies provided by different users). And storing (S30) the files on the server in a form that depends on the popularity of the files, files with a first level of popularity being stored in a deduplicated form and files with a second level of popularity being stored in an encrypted form, the first level of popularity being higher than the second level of popularity. More popular files may be seen as not intended to be confidential and therefore storable in a duplicated form. The method may further include repeatedly providing copies of the same file by different users, thereby increasing popularity of the file, and comprises storing said copies in a semantically secure encrypted form before the file reaches the first level of popularity, and in the deduplicated form after said file has reached the first level of popularity. The method may further include, upon the file reaching the first level of popularity, decrypting previously stored copies and performing deduplication on said copies.

公开(公告)号：GB2508390A

公开(公告)日：2014-06-04

申请号：GB201221558

申请日：2012-11-30

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  ENGELEN JOHAN B C ,  FURRER SIMEON ,  JELITTO JENS ,  LANTZ MARK ALFRED

IPC: G11B5/584

Abstract: A tape storage medium comprises at least one servo band SB along a longitudinal extension x of the tape storage medium TP for determining positional information such as lateral deviation for a position error signal. The servo band comprises a set of servo tracks ST1-6 extending along the longitudinal extension x of the tape storage medium and arranged next to each other. Each servo track of the set contains a servo pattern with magnetic transitions at a defined frequency f1-3, wherein the frequencies of magnetic transitions of servo patterns of adjacent servo tracks are different from each other. The set of servo tracks contains at least three servo tracks with magnetic transitions of different frequencies. Adjacent servo tracks may have orthogonal frequencies. Additional information such as longitudinal information may be encoded into the servo patterns. A tape head has at least one servo reader SR for reading the servo band and the width wSR of the servo reader is a least the width of a servo track wST.

公开(公告)号：GB2502579A

公开(公告)日：2013-12-04

申请号：GB201209690

申请日：2012-05-31

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  LANTZ MARK ALFRED ,  JELITTO JENS

IPC: G11B5/584 ,  G11B5/29

Abstract: A tape head for reading and/or writing data has a set of one or more segments SG where each segment of the set is individually movable with respect to a frame of the tape head. Each segment of the set comprises at least one of a write element W and a read element R, and a further read element FR. The width FRW of the further read element as a measure transverse to a motion direction of the tape is at least a width WW of the write element. The width FRW may be twice WW. The further read head may read servo information from a data band of the tape. A tape for storing data has data bands each comprising multiple data tracks extending along the tape, two or more servo bands extending longitudinally along the tape and a servo area in the data bands. The servo area extends transversely across multiple data tracks each having a servo pattern of different frequency F0*n where n may be a prime number.

公开(公告)号：GB2501521A

公开(公告)日：2013-10-30

申请号：GB201207338

申请日：2012-04-27

Applicant: IBM

Inventor： PANTAZI ANGELIKI ,  CHERUBINI GIOVANNI ,  JELITTO JENS

IPC: G11B5/584

Abstract: An apparatus for operating a tape storage device comprises a first tape skew determination unit DUS1 for providing a first tape skew value DTS1 concerning a skew of a tape in the tape storage device, and a second tape skew determination unit DUS2 for providing a second tape skew value DTS2 concerning the skew of the tape. An actuator SA adjusts one or more of a rotational orientation of a tape head and a motion direction of the tape, dependent on the first tape skew value and the second tape skew value. The first tape skew may be based on servo information prewritten to servo bands for allowing determining of a lateral tape position. The second tape skew value may be derived from two consecutive lateral positions of the tape detected by an optical detector.

公开(公告)号：DE112010004916T5

公开(公告)日：2012-10-25

申请号：DE112010004916

申请日：2010-12-17

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  PANTAZI ANGELIKI ,  JELITTO JENS

IPC: G11B5/56

Abstract: Verfahren zum Betreiben einer Speichereinheit mit einem Band (TP) und einem Kopf (HU), der funktionsmäßig in der Lage ist, Daten von dem Band (TP) zu lesen beziehungsweise darauf zu schreiben. Das Band (TP) ist in einer vorab festgelegten Längsrichtung (X) beweglich. Mindestens zwei aufeinander folgende aktuelle seitliche Bandpositionen (yx(t1), yx(t2)) des Bandes (TP) werden in Bezug auf einen vorab festgelegten Bezugspunkt (REF) an einer vorab festgelegten Längserfassungsposition ermittelt. Ein Bandschräglauf (&thetas;) des Bandes (TP) wird abhängig von den mindestens zwei ermittelten seitlichen Positionen (yx(t1), yx(t2)) festgestellt. Der Bandschräglauf (&thetas;) entspricht einem Winkel zwischen einer aktuellen Bandbewegungsrichtung (TMD) des Bandes (TP) und der Längsrichtung (X). Ein Schräglaufsteuersignal (uϑ) wird abhängig von dem festgestellten Bandschräglauf (&thetas;) bestimmt. Eine Kopfdrehposition (ϑ) des Kopfs (HU) wird abhängig vom Schräglaufsteuersignal (uϑ) so gesteuert, dass der Kopf (HU) an der aktuellen Bandbewegungsrichtung (TMD) in der Weise ausgerichtet wird, dass der Kopf (HU) funktionsmäßig zum Lesen und/oder Schreiben von Daten in der Lage ist.

公开(公告)号：DE112011100154T5

公开(公告)日：2012-10-04

申请号：DE112011100154

申请日：2011-02-18

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  HANCOCK REED ALAN ,  JELITTO JENS ,  TSURUTA KAZUHIRO ,  BUI NHAN XUAN

IPC: G11B5/584

Abstract: Ein veränderliches Zeitintervall wird von einem zeitabhängigen Servoband erfasst, um die seitliche Position eines Servolesekopfs zu ermitteln. Das Servoband ist in einer Folge von Blöcken mit nichtparallelen Servostreifen in sequenziell angrenzenden Unterrahmen eines linearen Magnetbands angeordnet. Die Zeitintervalle umfassen mindestens ein erstes Zeitintervall (A) zwischen einem ersten Paar nichtparalleler Servostreifen eines Unterrahmens; und ein veränderliches Zeitintervall (C) zwischen einem Paar nichtparalleler Servostreifen zwischen den ersten Zeitintervallen (A), wobei die Servostreifen des veränderlichen Intervalls der sequenziell angrenzenden Unterrahmen einen zweiten Servostreifen des ersten Paars und einen ersten Servostreifen eines sequenziell nachfolgenden ersten Paars umfassen. Bei Positionssignalen handelt es sich um Verhältnisse, an denen das erste und das zweite Zeitintervall beteiligt sind.