Data processor storage systems with dynamic resynchronization of mirrored logical data volumes subsequent to a storage system failure

Abstract

There is provided a system for dynamically resynchronizing a storage system made up of a plurality of mirrored logical volumes respectively divided into a plurality of mirrored logical data partitions in the event of a system failure. Immediately after the correction of the problem causing the failure, meals start to resynchronize the plurality of logical volumes but without waiting for the resynchronization to be completed; means access data from a data partition in one of said logical volumes. Then there are means for determining whether the portion of the logical volume containing the accessed partition has already been resynchronized, together with means responsive to these determining means for replacing the corresponding data in the other mirrored partitions in the logical volume with the accessed data, in the event that the portion of the logical volume has not been resynchronized. The means for replacing the data in the other mirrored partitions in the logical volume containing the accessed partition may replace the data prior to resynchronization of the logical volume or it may replace the data during the subsequent resynchronization of the logical volume. In the implementation where the data in the other mirrored partitions is replaced during resynchronization, then there is provided interim means responsive to the accessing of data from the data partition in said logical volume for indicating the partition as accessible and for indicating the other mirrored partitions in the logical volume as inaccessible.