Abstract: A data processing system for processing transactions, wherein a log record to be used for recovery of the system is written into a log file for system recovery in synchronism with the end of a transaction, and log records other than resident information are is written for a plurality of transactions into a log file for archives.

Abstract: A magnetic tape data management method and apparatus is described that reduces the access time for updating and referring to directory data. At the time of accessing data on a magnetic tape loaded in a magnetic tape subsystem, directory data for the magnetic tape is, in response to the completion of the processing of data, recorded in a region located near the place at which the magnetic tape head is positioned at that time, said region constituting a directory data region (DDR). Further, a directory data memory for recording directory data from the magnetic tape is provided in the magnetic tape subsystem, remote from the tape. At the time of accessing data on the magnetic tape loaded in the magnetic tape subsystem, directory data for the magnetic tape processing is, in response to completion of the processing of data, recorded in the directory data memory in the magnetic tape subsystem.