Patent ID: 7650476

Claim:
A method for generating a consistent point in time copy of data, the method comprises: selecting at least one selected data block to be copied from a source volume at a primary storage site to a remote target volume in response to a request to modify the at least one selected data block; waiting until the source volume is ready to send the at least one selected data block to the remote target volume while queuing at least one data block modify request; and de-queuing the queued at least one data block modify request while copying the at least one selected data block from the source volume to the target volume, wherein the copying comprises utilizing a first copying mechanism to copy the at least one selected data block if the request to modify the at least one selected data block is de-queued before the at least one selected data block is copied to the target volume; else, the copying comprises using a second copying mechanism that is slower than the first copying mechanism.