Mobile “off-grid” Data Center

Molly contains a little more computing power than typical in an overland vehicle. This little luxury makes it easy for us to use our laptops, ipads and iphones in seamless coordination with the computer infrastructure in Molly. The computer infrastructure is divided into three major functions; compute, storage and networking. The very same fundamental building blocks found in your typical data center.

In our last “around the world” trip, we had lot’s of issues with our collection of little portable hard drives, they continuously failed on us. This meant we constantly worried that we would lose our treasured photos, and we did lose some. This caused a little too much stress and countless wasted hours backing up photos. So we wanted to do things differently this time, with a more robust storage solution. For networking we added a wifi router, for reliable and easy local device to device communication, and to automatically connect to satellite, cellular networks and Wi-Fi hotspots when they are available. We are also seriously into maps, and the compute function tracks us with GPS, so we don’t have to worry about tracking ourselves.

The setup is a little complex, but hidden in this complexity is simplicity for us in our day-to-day travels. Here are the details.


As mentioned, we have had terrible luck in the past with reliable storage. So, this time we swapped our previous and more traditional Hard Disk Drives (HDDs) for more reliable Solid State Disks (SSDs). There are no moving parts in SSDs and therefore they tolerate the bumpy roads better. The Mean Time Between Failure for SSDs is typically around 2,00,000 hours versus 300,000 hours for HDDs. Other advantages of SSDs

  • Draw less power, about 2 to 3 watts per disk as compared to 6 to 7 watts for HDDs
  • Are faster with read and writes of 550MB/s and 520MB/s, compared to 50 to 120MB/s for HDDs respectively.
  • Need less cooling and fans, because each disk uses less power.
  • Are quieter, with no spinning disks and smaller fans.

Although SSDs have all of these advantages, the only reason we choose them is because they are more reliable. And we further increased the system reliability by placing them in a NAS (or Network Attached Storage) unit, which allows for RAID (or Redundant Array of Inexpensive Disks). This is obviously a little ironic, as these disks are anything but cheap. In fact SSDs are typically 5 times more expensive per gigabyte than HDDs. Our setup

  • Four Samsung SSD 860 EVO 2TB 2.5 Inch SATA III Internal SSD (MZ-76E2T0B/AM))
  • Installed into a Synology DS416slim NAS
  • Running RAID level 5, meaning we can tolerate complete failure of one of the four drives and not lose any data.
The Sold State Drive we use.
Network Attached Storage unit.

The NAS comes with a built in operating system and file management utilities. Synology has lots of features, like automatically backing up our laptops, can stream movies and music to our projector and iPads/iPhones and when connected to the internet, will backup our photos and files to another Synology device located in our New Zealand home. It is an all-round serious little device. Unfortunately the computer in the NAS is not powerful enough to run Docker containers.

Fortunately the DS416slim works off 12 volts, so is mostly compatible with of house voltage. It consumes around 17 watts when in use and 11 watts when idle. We placed a little voltage stabilizer and fuse between the house battery and the NAS, just to make sure it always gets 12 volts, even if the house batteries are a little low (or high). The NAS is hidden in our electrical cabinet; out of sight and out of mind.


For our computer, we decided on the Mintbox Mini 2 Pro from Compulab. This is semi industrial fan-less computer with ports for just about anything. It is running the linux Tara operating system.

Everything we do with this computer we could, in theory, do with our laptops, but the computer does it much more conveniently. No need to plug in cables or power it up for a task, as it is permanently connected to other devices and is always on. It runs 7×24 workloads, which is not possible on a laptop. Like the NAS, it is securely bolted down in our electrical cabinet.

It is a general purpose computer, so it can do just about anything, but for us it mainly does things related to tracking, mapping, data management and blogging. But more on that later.

The computer is 112 mm X 84 mm X 34 mm, weighs just 350 grams, consumes 5 to 15 watts with an operating voltage of 7 to 20 volts. It is hard wired into the NAS and the Cradlepoint modem, so we removed the wifi antennas. The power comes directly and unregulated from the house battery, but is fused.

We have also added a Raspberry Pi as our primary Internet of Things (IoT) computer. All the sensors are connected to the Raspberry Pi and the Raspberry Pi is connected to the network.


No expense was spared on networking equipment, with an industrial grade network router and modem from Cradlepoint. This provides our local wired and wireless network and can also connect to external satellite, cellular and hotspots for Internet. Networking is the glue between storage, the computer and all our wifi devices. It is also, securely bolted down in our electrical cabinet. It is connected directly to the house battery via a 3 Amp fuse, as it can operate on 9 to 33 Volts DC. At idle, it uses 4 watts, and upto 20 watts when transmitting on LTE and wifi.

Cradlepoint COR IBR900 600M with extensibility dock

The Cradlepoint COR IBR900 600M connects to the computer and NAS, but is also connected to Molly’s engine management system via the OBD-II port and a series of serial cables and adaptors based on the OBD-II Adaptor kit from Cradlepoint. We mounted a 5-in-1 antenna inside of Molly. This antenna has five elements, including GPS/GNSS, 4GLTE/3G/2G 2xMIMO and Wi-Fi 2xMIMO.

Why all of this Stuff

We are still working through what we will use this gear for. Here is a little more details on how we use this gear.

  • GPS Tracking Software. We constantly log our position into a database, and allow us to track where we have been. We have installed Traccar, which is an open source GPS tracking platform. We had to write some extra code so Traccar could understand the GPS and engine management messages coming from the Cradlepoint modem and the GPS messages coming from the ID-5100A HAM radio. We also had to change the Traccar software to make sure it could operate without an internet connection. Most importantly, now that it is setup, it is a zero effort to operate the system, with it quietly logging our track and one less thing for us to worry about.
  • Map Tile Server. The Traccar software requires a map, which is typically accessed on-line from the Internet. But obviously when we are in the middle of nowhere, there is no Internet. And we love our maps. So we installed our own map server, technically called a Map Tile Server. This server allowing us to bring up a detailed map for any place in the world. We use a base-map from Open Street Maps and open source software form Open Tile Maps. This solution is good, but not great, and really only allows us to view a very large collection of very detailed maps, but that’s about it. So our iPads also have maps, and more features for route planning and tracking.
  • Blogging with WordPress. The most useful feature the computer provides is being able to edit our blog while away from the internet. We have a full WordPress installation and a mirrored copy of our blog. We can create blog entries off-line and when we get into Internet coverage, can sync this entries with a single click of a button.
  • Backing up Files. We haven’t really sorted this out yet, but the plan is to have a simple seamless or 1-click backup solution. When we are out taking photos and return, we just want these photos to be backed up. Same for our laptops, they should be doing an hourly Time Machine backup automatically. The ultimate dream will be for the NAS to automatically back itself up to a remote NAS, whenever Molly strays into Internet coverage. This is certainly a feature of our NAS, it just needs to be configured.
  • Music and Movies. The NAS houses a copy of our music and movie collection. The NAS has a built in media server, allowing our laptops, iPhones, iPads and even our movie projector to connect to play music and movie files.
  • Database and Data Visualization. We use influxDB as our time-series database for storing IoT data and Grafana to visualize the data in the database. This is a very generic solution for data storage and visualization, including geo-coded data.
Computer and Cradlepoint in bottom right corner of Electrical Cabinet. Also, if you look carefully, in the top left corner is the Synology NAS.
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