bdsync - a fast block device synchronizing tool
Client: bdsync [--verbose] [--digest=DIGEST] REMSHCMD LOCDEV REMDEV
Server: bdsync --server [--verbose]
Patch: bdsync --patch[=DSTDEV] [--verbose]
Bdsync can be used to synchronize block devices over a network. It generates a "binary patchfile" in an efficient way by comparing MD5 checksums of 32k blocks of the local block device LOCDEV and the remote block device REMDEV.
This binary patchfile can be sent to the remote machine and applied to its block device DSTDEV, after which the local blockdev LOCDEV and the remote block device REMDEV are synchronized.
bdsync was built to do the only thing rsync isn't able to do: synchronize block devices.