The sources of lateral tape motion in a tape drive are reviewed. Currently used measurement methods and models for lateral tape motion are analyzed and compared. The effect of roller run-out, tape edge contact, and tape tension transients on lateral tape motion is discussed. A dual stage actuator tape head is investigated to improve track-following capability and increase the track density on a...

In [2] it has been shown that infinitary strong normalization (SN∞) is Π11-complete. Suprisingly, it turns out that infinitary weak normalization (WN∞) is a harder problem, being Π12-complete, and thereby strictly higher in the analytical hierarchy. We assume familiarity with infinitary term rewriting; we further reading we refer to [5,4]. 1 Infinitary Strong Normalization and Reachability Defi...

Introduction High frequency lateral tape motion (LTM) is a problem in tape technology that limits track density in a tape drive. To reduce high frequency LTM, it is important to identify all sources of lateral tape motion. The most important sources of high frequency LTM are edge contact between tape and tape drive components, non-repeatable roller axial run-out, air induced flutter and tape te...

Today large amounts of data are stored on tertiary storage media such as magnetic tapes and optical disks. DBMSs typically operate only on magnetic disks since they know how to maneuver disks and how to optimize accesses on them. Tertiary devices present a problem for DBMSs since these devices have dismountable media and have very diier-ent operational characteristics compared to magnetic disks...

Non-contact tension measurement of magnetic tape is performed. Light from a focussed light source is directed at a tape surface and the light reflected from the tape is captured by a photo cell. As the tape tension varies, the divergence of the reflected light bundle changes, i.e., the amount of light seen by the photo cell is a measure for the tension in the tape. Using this noncontact tension...

The IBM Virtual Tape Server provides a revolutionary tape storage solution that emulates tape drives using a disk cache, providing up to 256 virtual tape-drive images and stacking the virtual tape volumes onto a maximum of 12 physical tape drives. The high ratio of virtual to physical drives, combined with the stacking of virtual volumes, provides tape storage that is both costand space-efficie...

Lateral tape motion (LTM) is a function of tape path and tape properties, design parameters such as speed, tension, and friction between tape and tape path components. This investigation deals with the LTM of a tape moving over the surface of a cylindrical guide. Starting from the equation of motion for a moving tape on a cylindrical guide surface, the effects of friction, tape properties and d...

A growing number of applications require high capacity, high throughput tertiary storage systems [1] [2]. We are investigating how data striping ideas apply to arrays of magnetic tape drives. Data striping increases throughput and reduces response time for large accesses to a storage system. Striped magnetic tape systems are particularly appealing because many inexpensive magnetic tape drives h...

Measured replay pukes, recorded on Metal Evaporated tape, show a strong asymmetry and dependence on the direction of tape movement. It is found that pulse height and pulse width are unequal for both directions of tape movement. This is attributed to the non longitudinal easy-axis direction which causes differences in headtape geometry for both directions resulting in a different transition widt...

An accurate noncontact method of characterizing Ag-BiSCCO tape is reported, using the trapped field, , of a field-cooled tape. The dimensions of the tape make it possible to calculate in closed form a very simple expression, relating trapped field to transport current. Short lengths of tape, 4 (cm), are used to experimentally confirm the model. The model applies to any length of tape for which ...