Unison Support?

I wouldn't take that bet.

Hey Brendan. Ever since you wrote that, I've been wondering if you're right... thinking you probably were, but I wanted to know for sure. So I had a mental note to actually test it, once RAIDiator 4 shipped.

I just finally updated to RAIDiator 4, and (with a not-too-carefully tuned setup, for example I'm using the normal ethernet 1500-byte MTU, not jumbo frames), I get around 25MB/sec reads. Running md5sum locally, I was able to checksum a 700MB file in 27 seconds. Running md5sum against the same file locally on the NAS, it took 67 seconds (barely 10 MB/sec).

So you're right, and I lost the bet: the ReadyNAS can drop packets on the wire a lot faster than it can checksum them with md5sum.

I don't know exactly how rsync computes checksums and whether it's more or less CPU intensive than md5, but in the spirit of things, you win and that makes running rsync/unison on the NAS a lot less attractive, assuming a fast network (if you were running across a slow link, then of course the link becomes the bottleneck instead of the ReadyNAS's CPU and the tables may turn).