International Business Machines Corporation

Fahnmusa Christian Jangaba

Shawn Owen Brume

Christine Renee Knibloe

David Lee Swanson

Daniel James Winarski

Allen Keith Bates

Hirokazu Nakayama

Steven Ross Bentley

Mitsuhiro Nishida

Hisato Matsuo

Katsuhiko Hagiwara

Randall Scot Doan

Data is buffered for concurrent writing to tape. For a magnetic tape drive having a magnetic head with multiple sets of transducers; a drive mechanism configured to pass a magnetic tape past the magnetic head; interfaces from two different hosts; and at least one buffer configured to buffer data; and a control; the buffering comprises receiving data from two different hosts at the interfaces; buffering the received data in separate buffer space of the buffer(s) associated with each host, and adjustably size the separate buffer space for each host in accordance with a data transfer rate of the host associated with the separate buffer space; and concurrently writing data from the separate buffer spaces with the magnetic head to separate partitions of the magnetic tape.

Adjustable buffer sizing for concurrent writing to tape

According to one embodiment, a method for storing data on a magnetic tape comprises receiving data from two different hosts and simultaneously writing the data from the hosts to the magnetic tape using multiple transducers. In another approach, a method for storing data on a magnetic tape comprises receiving requests to establish a concurrent reservation from multiple hosts and allocating a unique stripe in a wrap to each of the hosts that sent the requests, wherein the wrap is a collection of data tracks to be written simultaneously in one direction of tape movement by multiple transducers of a tape head, and the wrap is logically divided into the stripes. Also, the method includes receiving data from the hosts and simultaneously writing the data from the hosts to the magnetic tape using the multiple transducers. Other systems and methods concerning storing data on magnetic tapes are described as well.

Multi-host concurrent writing to magnetic tape

A magnetic tape drive having a tape drive system for moving magnetic tape, tape read/write and servo system, tape cartridge load/unload systems, I/O communications, memory; and a control system, operates in three modes to conserve energy consumption. A first low power mode powers the I/O communications, the memory, and the control system. If a magnetic tape cartridge is in loaded position in the magnetic tape drive, the second low power mode powers the same as the first low power mode, and additionally powers the tape drive system to apply tension to a magnetic tape of the magnetic tape cartridge. In the first and the second low power modes, the control system operates the I/O communications, the memory and the control system to respond to and execute commands received at the I/O communications if the commands are executable without magnetic tape access. The third, full power mode, is entered if a command received at the I/O communications requires magnetic tape access.

Power mode operation of a magnetic tape drive

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Tucson, AZ, United States of America

Fahnmusa Christian Jangaba