The Raspberry Pi doesn't seem like a great choice for NAS. I know it has only 10/100 Ethernet which has to compete with the USB 2.0 (a particular problem if using an external drive). But it costs less, is quieter, and uses less energy than an old Pentium 4 box. But a mechanical hard drive would be a limiting factor for either a Pi or a i7.
So far I've found only two opinions on using the Pi for NAS, and neither said what NAS solution was in use. One person said it's just plain terrible. The other said it's mediocre, but good enough for one person to stream one HD video.
My usage is to be mostly documents/data files and audio. I'd guess most of these files are 10 megs or less, and there are tens of thousands of files. The total is 76 gigs, making an external drive necessary. I've thought about using an external SSD drive to further reduce energy usage (compared to a typical Pentium 4 box) and hopefully compensate a little for the speed of USB and 10/100.
For those who have tried OMV on the Raspberry Pi, how might it perform for my intended usage?