DataKeeper for Windows All Documentation - SIOS

Synchronous Mirroringvolume write, the write process on the target is terminated. The source system will complete the writerequest on its source volume, and the state of the mirror changes from Mirroring to Paused.In this diagram, Write Request 1 has already completed. Both the target and the source volumes have beenupdated.Write Request 2 has been sent from the application and the write is about to be written to the target volume.Once written to the target volume, DataKeeper will send an acknowledgment that the write was successful onthe target volume, and in parallel, the write is committed to the source volume.At this point, the write request is complete and control is returned to the application that initiated the write.While synchronous mirroring insures that there will be no data loss in the event of a source system failure,synchronous mirroring can have a significant impact on the application’s performance, especially in WAN orslow network configurations, because the application must wait for the write to occur on the source andacross the network on the target.DataKeeper for Windows Technical DocumentationPage 12