It's expensive for the home user only if buy the hardware sold by Coraid. There are kernel drivers that will let you export any local block device as an AoE target to your network, The Coraid devices just do this for you using dedicated hardware running Plan 9 (I kid you not...).

It's worth noting that the "expensive" is a relative term. At $day_job, we looked at a number of different storage technologies and vendors, and the Coraid hardware came out *very* nicely from a price/performance/capacity perspective. We have more than half a petabyte of storage on Coraid arrays, and have yet to find a way to do this as cheaply with any other storage vendor/technology.

The biggest bottleneck we have is the Linux NFS stack (which should come to no surprise to anyone). In my testing, I got comparable performance numbers between an SR2461 and our NetApp filer up to about 10 concurrent clients, at which point Coraid performance dropped off signifcantly. I suspect this was, as mentioned, due more to Linux choking on the NFS traffic rather than the array not being able to handle the load.

Is it perfect? No, but works and scales pretty well for us.