Patent ID: 7124258
Filing Date: 2006-10-17
Classification: G06F

Abstract:
1. A storage system employed in a hetero-environment in which a main storage system is connected to a sub-storage system, the sort of which is different from the sort of said main storage system, for transmitting/receiving data between an upper grade apparatus and said storage system, wherein said main storage system comprises: receiving means for receiving data and a data writing request from said upper grade apparatus; data holding means for holding the data, which is required to be written in response to said received data writing request; transferring means for transferring to the sub-storage system, a copy of the data which is required to be written, in response to said received data writing request; and data guaranteeing means for guaranteeing whether or not said data copied to and held in said sub-storage system corresponds to correct data; wherein in said hetero-environment, said main storage system and said sub-storage system connected thereto respectively employ different guarantee functions to guarantee the correct transfer of data during data transfer operations; wherein the data guaranteeing means is arranged to receive, from the sub-storage system, the data copied to the sub-storage system and read out therefrom, and to store the data received from the sub-storage system at least until the guarantee; and also to receive, from the data holding means, the data held in the data holding means; and, wherein according to the guarantee function employed by the main storage, the data guaranteeing means compares the data received from the sub-storage system with the data received from the data holding means, judges whether the data received from the sub-storage system is identical to the data received from the data holding means, and if the data are not identical to each other, outputs an error notification, in response to which the transferring means again transfers the copy of the data to said sub-storage system.