ZFS Replication To the Cloud Is Finally Here and It's Fast (arstechnica.com)

New submitter kozubik writes: Jim Salter at Ars Technica provides a detailed, technical rundown of ZFS send and receive, and compares it to traditional remote syncing and backup tools such as rsync. He writes: "In mid-August, the first commercially available ZFS cloud replication target became available at rsync.net. Who cares, right? As the service itself states, If you're not sure what this means, our product is Not For You. ... after 15 years of daily use, I knew exactly what rsync's weaknesses were, and I targeted them ruthlessly."

Comments

rsync and zfs do different things

[MichaelSmith]

rsync synchronises files. ZFS synchronises a file system. Of course it is better to work that way because you can transfer just the changed components of a file. Moving a file just changes a pointer, so send the pointer. That sort of thing.

Re:Rsync could have done this too!

[brambus]

The crucial difference is ZFS send is unidirectional and as such is not affected by link latency. rsync needs to go back-and-forth, comparing notes with the other end all the time. ZFS send is also a lot faster and more efficient, eliminating entire large portions of the filesystem tree structure that haven't changed without having to read them in. This is not to say that rsync's authors were any less competent coders. ZFS simply has more information available about the filesystem than rsync, so it can make smarter decisions.