I'm new to Hitachi Storage and I'm trying to understand the difference between creating a pair relationship that is part of a consistency group versus one that is not. In my reading on this it appears that a consistency group won't allow a split until all I/O has been written to the shadow/remote copy. I've also read that if the host requests I/O to the PVOL and a split operation is in progress that I/O request won't get served until the split is completed. Am I understanding this correctly? In the case of the host wanting to write or read to the PVOL during a split, wouldn't a delay in this request create errors on the host side? If anyone could shed some light or point me to a white paper or real world situation I'd appreciate.