Editor’s Note: Customers of CTERA have a fair share of weekend hackers and tinkerers and so – despite our official policy of not introducing physical changes to our appliances and the voiding of the warranty — we can’t help but appreciate this DIY project from one of our long-time users. This blog post was written by an admin at a global but anonymous enterprise customer who modified our C200 cloud storage gateway appliance for use at home instead of a branch office. Given that CTERA supplied the world’s largest deployment of cloud storage gateways, and with our ROBO storage gateway appliance capacity reaching 64 TB, it should be clear that our products are built for global enterprises with multiple remote offices, not home users.

I’m Steve Lloyd and I’ve been running a C200 unit as a home storage and backup device for the last 18 months. I’m using it to host several Windows File shares (SMB) for my photographs and documents and I’m backing up three separate clients to the C200 using the included agent. I configured it up to replicate the backups and shares to a CTERA instance running in AWS.

As a device, it does what it’s designed to do and spins along with little interaction whilst looking a little bit ‘enterprise in the home’ due to its design as a business-market device. However, as I have a background in designing and building one-off custom cameras I decided to use my skills – along with a 3D printer and some solder – to reimagine the C200 as a home backup device for the modern smart house.

Before I started the disassembly, I thought about the current positive/negative points of the C200 for use at home:

Pros

Relatively small.

The colour-scheme is ‘enterprise-grey’ so isn’t particularly invasive.

Hardware-wise it’s a very stable device, performing its role with limited intervention.

Easy to replace the drives in the event of upgrade or failure.

Cons

‘Enterprise-grey’ doesn’t make a bold statement for a smart home.

Not silent because the 3.5” disk drives are fan-cooled.

Although the C200 is smaller than a server, NAS devices designed for personal use are considerably smaller.

The design is a little ‘solid’, so a sleeker body would a better fit for the home market.

After comparing the pros and cons, I decided to base my new design on four key points:

Reduce the footprint

Improve the appearance

Reduce the noise

Flexible standing options

The first step was to disassemble the C200 to get to the motherboard and work out how I could reduce the overall footprint. After taking it apart, I was happy to find that the mainboard is a single unit with a simple riser board, twin SATA cables and combined power cable to connect the two 3.5” disk drives.

Whilst the 3.5” hard drives are inexpensive, they use fans for cooling – but 2.5” drives are designed to run in uncooled environments and don’t have any fan noise. The cost of 2.5” drives are close enough to 3.5” drives and I don’t need the extra speed and durability of the larger drives, so I really hoped I could use the 2.5” drives to condense the chassis.

Another positive discovery was that the internal fan is only used to cool the HDDs and not the mainboard itself, meaning that by replacing the 3.5” hard drives with 2.5” drives I could also remove the fan. This would mitigate both the issue of noise and overall size/footprint.

Once the entire C200 was disassembled, I started measuring up the board to help with my 3D modelling to design the most compact unit possible. As well as the basic port locations, I also looked at the tallest components on the board as I was planning to mount the both 2.5” HDDs in a caddy above it. After taking all measurements, I found that the onboard battery was the highest component so I had to mount the HDD caddy at least 15mm higher than the mainboard. With this information, I could begin the task of modelling the new chassis.

I use Google Sketchup to do my 3D modelling, as it’s relatively simple and can output the required STL files for 3D printing. The first step was to draw up the mainboard. Along with all of the connectors/ports that needed be factored into the chassis, the onboard battery and the indicator LEDs were also included as I would need to laser cut new acrylic light pipes to output them to the front of the case.

Once I was happy with the mainboard layout, I could starting building the new chassis around it. Whilst keeping the chassis compact was important, I also had to ensure enough airflow around the board and HDDs as I wanted it to run fanless.

After trying a few different designs, I settled on a rounded-corner layout with slim vents on two sides. The other two sides contained the input/ports and indicator LED output.

Once the main chassis was complete, I drew up a slim lid with Ctera branding. The Ctera logo would be cut out with a fine mesh below to provide adequate airflow for the HDDs, which would be mounted directly below. The caddy itself is made up of two simple frames that surround the HDDs and are then joined together with supports and screws. The complete caddy/HDDs is then slotted into support trays built into the side walls of the main chassis. Whilst the HDD caddy is held in place through friction, the lid would be secured using a 2mm deep lip on all four sides and four small screws on the outside.

Once I was happy with the virtual design, the next step was to print a ‘mule’ unit to test the fit/layout. The bed on my 3D printer isn’t large enough to print the chassis/lid in one so I split the chassis model into 4 pieces and printed them separately. These pieces were then bonded together and a test lid was cut from foamboard.

After completing the test print, I found that I needed to adjust the size by 5mm to account for the mounting points on the board but it was useful to see the overall layout and compare my design to the original C200. I was also able to test fit two 2.5” HDDs and ensure that they did not catch on any of the board components.

After confirming the overall layout of the model, I moved on to the physical connectivity required to fit the new HDDs. The original drives used a riser board to provide power along with short dual SATA data cables. I swapped one of the SATA cables for a longer one to allow me to mount the new HDDs side by side and then combined the original data cable with two new right-angle SATA power cables.

By combining the original cable with two new right-angle SATA cables, I could retain the original mainboard connector to provide power. I would shorten the new cables once the drives were installed to keep the installation as compact as possible.

At this point, I wanted to test the performance of the Gateway using the new HDDs so I connected it to my network and booted it up. After a minute, the gateway was allocated an IP via DHCP successfully and I could logon to the web interface. Once in the web interface, I tested formatting the HDDs and creating both a JBOD and RAID1 array across them. These both worked as expected and I was able to create a share then mount it from my client, showing that the mainboard was functioning correctly with the new HDDs and cabling.

After this successful testing, I uploaded my STL files to a professional printer and waited for my completed parts to arrive. The four parts I ordered, (chassis, lid and two HDD caddies) took around 10 hours to print and I received them back in the post a few days later, ready for final assembly.

The first job was to mount the HDDs in the caddies and join them together. This is done with a combination of screws and push-fit mounts to create a stable tray for the disks. Once the disk caddy was ready, I fitted the mainboard into the chassis and connected the dual power and data cables. The completed tray was then mounted into the chassis and the SATA power cables were shortened to match the final HDD locations.

After this, the lid was screwed into place and the first fit was complete. This is the final printed unit alongside my first test mule unit. The final unit is 35mm deep by 170mm square.

Once I was happy with the fit and finish, I drew up and printed a mock branded mesh plate and bonded it to the underside of the lid. In the long term I will replace this with a genuine mesh to allow better airflow although currently, the gateway is running at a constant 41 degrees so is not being adversely affected by the mesh not being in place.

The final parts I needed to manufacture were the acrylic light pipes. These are required to bend the light from the indicator LEDs through 90 degrees so that they can be seen from the side of the unit. I couldn’t use the original part because my new unit is considerably slimmer so I drew up a new mount and individual pipes which were then laser cut from 4mm clear acrylic.

The final assembly was then completed by slotting the right angle pieces into the main holder and securing them with adhesive. Once complete, the new part was then slotted into the chassis, above the main board, and bonded into place. I bonded a sheet of heavy black card to the side of the chassis, around the light pipes, to stop any stray light showing through the printed walls.

At this point, my reimagined C200 is complete and christened the C100, ready for a new smart-home market where connected devices are commonplace and the fear of losing data is of high concern.

I have been running my C100 as a home backup server with cloud integration for several weeks. Apart from the initial confusion of whether it was on or off due to it being silent (!), I’ve met all of my original objectives with the design and implementation. I now have a home-friendly unit that continues to perform the ongoing storage and backup of my documents and clients to the cloud while consuming considerably less space in my office.

Maybe sometime in the future I can get my “C100” device included in the GUI. For now, I made a mock-up: