Browse Prior Art Database

Saving Data in a Partitioned Buffer Upon Power Failure

IP.com Disclosure Number: IPCOM000049818D
Original Publication Date: 1982-Jul-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Videki, ER: AUTHOR

Abstract

A host is connected to a plurality of magnetic tape recorders via a dynamically partitionable buffer. The buffer contains selected data for being written to the tape recorders or being read from the tape recorders. Generally, the amount of data in the partitioned buffer to be recorded on the tape recorders is minimal. A power-failure sensor detects an upcoming failure, such as an increase in current, decrease in voltage, or a substantial phase change, to cause all the data received from the host to be written to the tape recorders in accordance with an asynchronous control. A control activated by a power-failure sensor causes all tape recorders which are to receive data to move tape. When high density recording is employed, tape only moves a vary short distance.

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Saving Data in a Partitioned Buffer Upon Power Failure

A host is connected to a plurality of magnetic tape recorders via a dynamically partitionable buffer. The buffer contains selected data for being written to the tape recorders or being read from the tape recorders. Generally, the amount of data in the partitioned buffer to be recorded on the tape recorders is minimal. A power-failure sensor detects an upcoming failure, such as an increase in current, decrease in voltage, or a substantial phase change, to cause all the data received from the host to be written to the tape recorders in accordance with an asynchronous control. A control activated by a power-failure sensor causes all tape recorders which are to receive data to move tape. When high density recording is employed, tape only moves a vary short distance. The control then activates the transfer of data from all of the partitions in the buffer that have data not yet written on tape recorders. In this manner recovery from a power failure results in data being recorded in the recorder that it was originally intended, thereby simplifying recovery.

The drawing shows several tape recorders MTO-MT4 and MT6-MT7. Recorders MT4 and MT6 are reading data to the host; hence, they are not subject to the recovery from a power failure being sensed. MT7 is in a rewind or locate mode; hence, it is not logically connected to the partitioned buffer, and is not affected by the recovery procedure. MT0, MT1 and MT3 are to re...