Data recovery system capable of performing transaction processing in parallel with data recovery processing

For use in a computer system, a data recovery system comprises an information producing unit for producing block-up information for data blocks which must be recovered to before images after occurrence of a system failure. Before such data blocks are recovered, other data blocks are either subjected to a transaction processing program or stored in a data file without waiting completion of the data recovery. The data blocks for which the block-up information is produced, are either subjected to the transaction processing program or stored in the data file after a block-up releasing unit deletes the block-up information upon completion of the data recovery. The data recovery system is operable even upon occurrence of an additional system failure during progress of the data recovery.