Tape dimension compensation

Patent metadata

Field	Value
Publication number	US-9299375-B2
Application number	US-201414546112-A
Country	US
Kind code	B2
Filing date	Nov 18, 2014
Priority date	Dec 18, 2013
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

In response to determining that a first write operation is to be performed on a portion of tape, writing data to a data track with a tape head element spacing at a nominal value. A tape width of one or more tape positions at which data is written is recorded. In another aspect, a tape width value associated with a tape is retrieved. A current tape width value associated with the tape is determined, and the tape head element spacing is set based on a difference between the retrieved tape width value and the determined current tape width value.

First claim

What is claimed is:

1. A method for compensating for tape dimensional changes, the tape being wound within a tape cartridge, the method comprising:
in response to determining that a first write operation is to be performed on a portion of tape;
setting a spacing between tape head elements, with respect to the direction of travel of the tape over the two tape head elements, to a nominal value by one or more of setting a tape head azimuth angle, and setting the physical spacing of tape head elements relative to one another, wherein the nominal value is based on a specification or standard associated with a tape technology, and on a function of tape position that compensates for the widening of the tape at inner diameters of the tape cartridge;
writing data to tape blocks of a data track;
determining tape widths at tape positions of one or more of the tape blocks to which the data is written, based on a width of servo tracks at the tape positions and the tape head element spacing nominal value, wherein the positions of the one or more of the tape blocks to which the data is written are based on one or more of a predetermined tape distance interval, or the beginning of each tape block; and
recording in a data store associated with the tape the determined tape widths and the tape head element spacing nominal value;
in response to determining that a requested tape operation to a tape is not the first write operation;
retrieving the recorded the determined tape widths and the tape head element spacing nominal value;
setting the tape head element spacing, with respect to the direction of travel of the tape over the tape head elements, to the retrieved tape head element spacing nominal value as the function of tape position by one or more of setting the tape head azimuth angle, and setting the physical spacing of tape head elements relative to one another; determining a current tape width value associated with the tape; and adjusting the tape head element spacing as the function of tape position, with respect to the direction of travel of the tape over the tape head elements, by one or more of setting the tape head azimuth angle, and setting the physical spacing of tape head elements relative to one another, based on a difference between the retrieved one or more recorded tape widths and the determined current tape width value.

2. A method in accordance with claim 1 , wherein recording the tape width of one or more positions in a data store associated with the tape comprises one or more of:
recording the tape width in a media auxiliary memory of a tape cartridge of the tape;
recording the tape width in an electronic non-volatile memory of a tape cartridge of the tape;
recording the tape width on the tape; and
recording the tape width on a computer-readable tangible storage medium of a host computing system in communication with the tape head.

Assignees

• IBM

Inventors

• Herget Philipp

Classifications

• G11B27/36

  Monitoring, i.e. supervising the progress of recording or reproducing {(for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06)} · CPC title

• G11B20/10

  Digital recording or reproducing · CPC title

• G11B5/584 Primary

  for track following on tapes · CPC title

• G11B5/56

  with provision for moving the head {support} for the purpose of adjusting the position of the head relative to the record carrier, e.g. manual adjustment for azimuth correction or track centering ({G11B5/52,} G11B5/54, G11B5/58 take precedence) · CPC title