FAULT TOLERANT SERVER, ITS MEMORY COPY METHOD AND MEMORY MODULE FOR STORING WRITE ADDRESS DATA

PROBLEM TO BE SOLVED: To make a time shortening function for memory copy generally available, and avoid difficulties in implementation.SOLUTION: A fault tolerant server 300 implements a memory module 400 for storing write address data in a memory slot 305a. A memory controller 411 for storing write address data accumulates write addresses to main memory 313 in memory 410 for storing write address data. A memory copy engine 306a outputs the write addresses accumulated from the start of one system operation caused by fault occurrence until the time when duplex operation is recovered after termination of the one system operation to a memory bus, reads the data stored in the main memory 313 corresponding to the outputted write addresses, and copies the data to main memory of the other one system which is recovered from the fault.