I should take my second post of the new year to mention that I love raspberries. I’m not sure if they’re my favorite, but they’re damn close. I’m not sure what else to say, other than try some in champagne, or other drinks. Try them with cakes. Candy bars containing raspberry are good as well.
This post, however, is not about the berry, but the Raspberry Pi, a tiny embedded Linux system that boasts enough power to be a full-featured desktop. (If you came upon this post, you’re probably already somewhat familiar.) There are two models, at $25 and $35. The more expensive one has two USB ports as well as an Ethernet port. (The lesser, I believe, only has one USB and no Ethernet. But, you could get a hub.) Both have a 700 MHz ARM-based CPU, and 256 MB of RAM. They are surprisingly capable graphics-wise (check out the link for more details), and they are also low power. This is what interests me.
I posted before about possibly configuring my Web server to run at least partly on solar power. On that post, someone commented on the possibility of using the Pi for this. And so, I have a model B on order – this board uses about 3.5 watts, so that’s a start. I would use an external USB drive for much of the filesystem, which would bring this up some, but it should still be less than my current setup which consists of a Mini-ITX board (about 1 GHz, with 256 MB RAM and a 120 GB hard drive).
I have a model B on order (should come in May), and my plan is to throw Debian on there and test this out. My current server does a decent amount, but it doesn’t seem to get overtaxed. I’d be looking to run Web (Apache; yes I know there are smaller servers that might work, but I’d like to try this), PHP, MySQL, Email (Postfix/Courier), and LDAP (Email backend). This should be interesting, and if I make careful use of the onboard SD card I think there’s a shot that this could turn out well.
As for power, part of the inefficiencies of my current setup (roughly 30-4o watts at the plug) are due to the power supply. With a much smaller supply I should be able to bring this down. As I also mentioned in the other post, I would like to come up with some sort of power sharing solution, where the primary power source for the Pi is solar, with the mains as a fallback and a battery backup in case of a power failure. The idea would be to keep a normal system battery charged, rather than taxing it by cycling it each night to keep the server running. Maybe someday I’ll end up with so much solar that the ~10 watts the whole setup should draw will be a drop in the bucket 24 hours a day (10 * 24 = 240 watt-hours/day), but for now I would take this approach. (Also, a backup battery is good for other things, and I probably won’t care much about my Web server compared to, say, charging the cell phone or pumping out the basement.)
If the Pi isn’t up to this, I’ll probably try it with a media center-type application, and maybe look into a Sheevaplug for the server. (It has USB also, so I could literally almost drop it in place.) My server does get its fair share of hits, between this site, the Fever Dreams mirror, and when I host images on message boards like Fark. But, I think that a small machine should be fine.