[Frank] knows how important backups are for data security, but his old method of plugging a hard drive in to take manual backups every so often is not the most reliable or secure way of backing up data. He realized he was going to need a secure, automated solution. He didn’t need a full-sized computer with a ton of power; why waste electricity for something so simple? His solution was to use a Raspberry Pi as the backup computer.
The main problem he faced with the Pi was finding a way to make it rack mountable. [Frank] started with an empty 1U server case. He then had to bend a few metal plates in order to securely mount the backup drive into the case. A couple of small rubber pads help dampen any vibrations caused by the hard drive.
The computer power supply was able to put out the 12V needed for the hard disk, but not the 5V required to run the Pi. [Frank’s] solution was to use an LM2596 based switching supply to turn the 12V into 5V. He soldered the power supply wires directly to the Pi, thinking that a USB plug might vibrate loose over time. Mounting the Pi to the computer case should have been the trickiest part but [Frank] made it easy by simply gluing the Pi’s plastic case to the inside of the computer case. When all was said in done, the backup server pulls 29W under full load, 9W with the disk spinning, and only about 2W in an idle state.
On the software side of things, [Frank’s] backup box uses bash shell scripts to get the job done. The Pi connects to his main server via VPN and then the bash scripts use rsync to actually collect the files. The system not only saves backups every night, but also keeps week old backups just in case. If you are really paranoid about your backups, try hooking up a custom battery backup solution to your Pi. If a Pi just isn’t doing it for you, you can always try one of many other methods.
[Coke Effekt] wanted to push his server’s storage limits to a higher level by combining ten 3 TB drives. But he’s not interested in transitioning to a larger case in order to facilitate the extra hardware. It only took a bit of hacking to fit all the storage in a mini-ITX case.
His first step was to make a digital model of his custom drive mount. This uses two 3D printed cages which will each hold five drives mounted vertically. To keep things cool the two cages are bolted to a 140mm fan. The connections to the motherboard also present some issues. He uses a two-port SATA card which plays nicely with port multipliers. Those multiplier boards can be seen on the bottom of the image above. The boards are mounted using another 3D printed bracket. Each breaks out one of the SATA ports into five connections for the drives.
Kiss that energy hungry PC you’ve been using as a home server goodbye. [Vince Loschiavo] shows us how he squeezed a remarkable amount of functionality out of an inexpensive Android stick which manages his home’s digital empire.
He started off just wanting some network attached storage. For this he grabbed an MK802 Android Stick which you can get for a song if you find the right deal. To bend it to his will he said goodbye to the Android OS, installing Ubuntu for ARM instead. The stick (which is missing its case in the image above) connects to a USB hub in host mode, but does actually draw all of its power from the hub itself. This made it possible to attach a USB to Ethernet adapter to boost the speed which would have been limited by the WiFi connection. There’s a 320 gig USB hard drive for the storage. With that much space on hand it makes sense to add streaming media service as well which is simple since it’s running Linux. The last part of his work actually turns it into an Asterisk server by way of Google Voice and a SIP phone. An impressive outcome at a bargain price to be sure!
Here’s an interesting use of a Raspberry Pi to control the PSU on a server. [Martin Peres] is going to be away for a few months and still wants access to his PC. This isn’t really all that tough… it’s what SSH is made for. But he also wants lower-level access to the hardware. Specifically he needs to control and get feedback on what the PSU is doing, and even wanted to have access to the serial console without having to go through the computer’s NIC.
The image above shows one part of his solution. This is a custom Ethernet port that connects to his Rasberry Pi header breakout board. Inside the computer the jack is wired to the motherboard power LED to give feedback about the current state of the power supply. It also patches into the green wire on the PSU, which lets him turn on the power by pulling it to ground. After working out the cable routing he developed a web interface that makes it easy to interact with the setup.
As with other hacks along these lines letting an embedded computer run 24/7 is a lot less wasteful than leaving a PC on. That’s a concept we can really get behind.
Continue reading “RPi control your server PSU over the Internet”
Take a look around here and you’ll find all kinds of embedded web servers. This one doesn’t look all that interesting, especially because it’s just a NIC plugged into a development board. But for us the interesting part is in how [Andrew Rossignol] chose to format the webpage assets to best utilize the under-powered server.
The project was spawned as part of a class in Internet Embedded Systems which [Andrew] is taking. The board has an ATmega16 microcontroller and he’s using the ever popular ENC28J60 on that Ethernet adapter board. The TuxGraphics TCP/IP Stack takes care of communications with the network.
One constraint which [Andrew] imposed upon himself was to use just a single response which the available RAM limits to about 700 bytes. Any decent webpage needs to have at least some graphics but that’s tough with the size limit. He managed to display an AVR logo by optimizing an SVG in Inkscape then stripped the rest of the cruft using VIM (explained in the demo after the break). With that piece of Linux-fu in his pocket he set to work streamlining the CSS file. The webpage isn’t just static either. He displays the server up-time and even allows the relays and LEDs on the Olimex board to be controlled.
Despite the limitations of the ATmega family they still seem to do some amazing Internet-connected stuff. Here’s one used as a Minecraft server.
Continue reading “Embedded web server is all about clever formatting”
We love using Git for its superior version control. We often host our more advanced projects in a public Github repository. But the bulk of our little experiments are simply local repos. This is fine if you’re always at home, but if we are away from home we find ourselves having to SSH into our server to copy over the Git files. [Andrew] found a way around this slightly awkward process. He used an old Android phone as a Git server.
This actually makes a lot of sense when you start to think about it. Most Android phone have a microSD card slot to provide a huge storage bin (the lack of this on the Nexus 4 is baffling) so you don’t need to worry about running out of space. All of these devices have WiFi, making it easy to use them as an AP when there isn’t any other WiFi around. And the web-connected nature of the device will make syncing your repo over the Internet a snap.
Most of the behind the scenes work is done using Debian packages. This provides a few issues which [Andrew] walks through one by one. We also like his pointers like using ‘noatime’ on your EXTx file systems to avoid wear on the SD card.
This hack could be titled ‘Exercise or Starve’. [Charalampos] needed some motivation to become more active. There’s a device called a FitBit tracker (black and blue on the left) which records your activity and submits it to a web interface. You get daily goals and can earn badges. But those stinking badges didn’t motivate him. He decided he needed something that would really get him off of the couch. So he hacked the FitBit to cut power to his refrigerator. Not meeting his goals will eventually result in a stinky mess and no dinner.
It’s a bad idea to cut power to the icebox. But we see this merely as a proof of concept. He’s using the Belkin WeMo networked outlet. Other than some security issues we discussed on Thursday this is a very simple way to control devices from your server. [Charalampos’] implementation uses the FitBit API to check his activity and drives the outlet accordingly.