Web, mail and DNS master for gdt.id.au
RPi Model B 512MB
Raspbian, latest, modified to boot from SD card, root on hard disk
2TB USB-attached hard disk.
Headless, with serial console is connected to a USB dongle.
Web using Apache, IMAP mail using Postfix/Dovecot/SpamAssassin/ClamAV, DNS using BIND.
Does about 80Mbps, which is respectable for 12 watts, but does show the effect of the single USB bus attaching to both the fast ethernet and USB disk. These days I'd consider a different single-board computer with gigabit ethernet and SATA, but the power consumption would be much higher and thus probably not worthwhile for a vanity web site.
Home internet gateway.
RPi Model B 512MB
16B SanDisk SD card (and spare with copy of image)
Raspbian, latest, only major mod to send syslog back to dmesg buffer rather than write to SD card.
Connects via ethernet to "home area network" fast ethernet switch; connects via USB to ADSL2 bridge to ISP; connects via USB to a old Samsung personal laser printer.
The purpose of this is twofold. Firstly, the printer isn't supported by drivers for the latest Windows or MacOS. So these can print using their generic PostScript driver to the RPi actiing as a print server. It interfaces with printing systems used by Apple IOS and Google Android too, making my old printer more capable than most printers currently being sold. Secondly, I wanted to expand my understanding of IPv6 by implementing a home IPv6 gateway, this is described in my blog
What I liked about the RPi is that there's just enough resources to run the widely-used software for a server application -- I don't need to fiddle about with software designed for small embedded systems. I can use Apache, BIND, Postfix and so on and not face the higher costs of using software outside the server mainstream.
The mounting is simple enough -- nylon screws and nuts through the mounting holes into the steel of a 1RU 19in rack shelf. These simply hold the RPi about five millimetres above the shelf. Additional holes are used to bolt the USB hard disk to the shelf and to pass through touchtape cable ties to control cabling.
I used a RS-232-3.3v to USB dongle to give a serial console. This dongle is mounted to the rear of a USB B-A through-connector designed for use on a wall plate. I mounted a half-height wallplate on the front of the shelf. The result is that to connect to the serial console you plug a USB A-B cable from your PC into the USB socket on the front of the shelf. Also on the front of the shelf is a reset push button (running to P06-1+2) and a 240VAC switch to power-down the entire shelf. The result is a very datacentre-friendly presentation in 1RU. The layout allows for 3 RPis+disk per 1RU shelf.