I am not familiar with nasuni, but the general idea is that once bvckup2 has the block hashes for the source file, it will write only modified blocks to the bac

I am not familiar with nasuni, but the general idea is that once bvckup2 has the block hashes for the source file, it will write only modified blocks to the backup copy. Block hashes are computed either when the file is first copied to destination (by bvckup2) OR when the exact copy already exists at destination and the backup job is set to do "delta pre-comp" [1]. If in your case the latter applies, you may in fact get away with setting up delta copying without pulling any data off the cloud storage. [1] https://bvckup2.com/support/forum/topic/1131 https://bvckup2.com/support/forum/topic/1131