Revolution in low-power NAS

Even though I’m a Mac user at home, I hadn’t been paying attention to a revolutionary step forward in lowering power consumption.

I’m speaking of the “Wake on Demand” feature in Snow Leopard and Airport routers.  This is a combination of router + OS trickery that has great potential for allowing machines to go to sleep (i.e. 1w – 3w power usage), while the router acts as a proxy for the sleeping machines and acts as a proxy for the sleeping server.  If another machine attempts to access the server, the router will send the magic WakeOnLan packet (or WakeOnWifi equivalent) to the server so that it can handle the request.

I haven’t figured out how exactly it works, but most attempts to connect to a sleeping Mac via either SSH connections, VNC, SMB, or AFP will trigger the wakeup.  The underlying infrastructure is Bonjour/ZeroConf based, and I think the new router “sleep proxy” could easily be integrated into OpenWRT or other firmware, but more interesting is how Apple might have had to tweak their OS to get Bonjour involved in things like opening an SSH connection to another machine.  For example, I would have thought vanilla OpenSSH would use raw sockets instead of a Bonjour API, so I wonder whether Apple has had to modify all of its common client software packages to play well with this infrastructure?

If this can be spread to other routers and NAS operating systems, it would bypass the need to optimize idle power consumption with exotic Atom-based motherboard, etc.  A low-cost Core i3 with mainstream H55 motherboard already beats or gets very close to an Atom board in terms of idle consumption, but actually letting your server go to sleep is a order of magnitude improvement over either.

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