In order to implement a reliable data sync sub system based on IP network and provide transparent mirror storage for up level applications, an IP based remote data sync method was presented. This method simulated a SCSI disk device which supports standard SCSI disk device instructions. The SCSI disk device was composed of two disks, one is the native disk in the local server and the other is the remote disk in the remote server. When a writing operation is issued to the SCSI disk device, the data is written to the native disk, and at the same time, the data is sent to the remote server, where the same writing operation is performed to the remote disk. This method provided real time data sync without affecting the business continuity of working systems, supported inexpensive two site storage and enhanced the reliability of the application system.
