Home computer lab
I will describe here what I did in order to solve two issues I have been facing. First the lack of memory and second the lack of CPUs for virtualized environments. To fix it, I decided to look for a professional grade server at the lowest possible cost. In short, I found a second hand server on ebay to which I made a few adjustments.
Currently This is what I’m starting with:
- Desktop computer (Quad-Core Intel Core i5-4430 3.0 GHz + 8 Go DDR3 1600 MHz):
- Running time: when needed.
- Usages: development, exploratory analytics, virtualization.
- Average power consumption: 100W (incl. screen).
- Low power linux computer (Intel ATOM 1.6 GHz + 1Go DDR2 400MHz)
- Running time: 24H.
- Usages: databases, files storage, ETL scripts.
- Average power consumption: ~.
- Raspberry Pi Type B+ (ARM11 700 MHz + 512 Mo RAM)
- Running time: 24H.
- Usages: media center, experimentations.
- Average power consumption: 2.5W.
This is a confortable setup as I’m able to have at least one computer running all day long without having too much impact on my electricity bill. But it has its limits. All the “serious” work is done on my desktop computer on which create a VM per project I’m working on. My VMs are often starving my desktop computer memory so I decided to get another system to run more virtual environments.
I turns out it is actually really cheap (200$~300$) to get a used server from eBay. Slower than newer servers but more than enough for personal use.
What do you actually get for this kind of money? The listing on eBay is quite interesting you see a lot of 4+ years old servers mainly from HP and Dell. Already 5 years ago it was not uncommon have Quad-cores CPU, usually 2 or 4 of them in one box, and large quantity of RAM from 8GB to 128GB. For the price range I mentioned you can easily get a 2 to 4 Quad-Core with 16GB to 64GB of RAM and 0 to 2 hard drives.
In comparison a new computer with 16GB of ram cost 500$+ and 350$+ for the 4GB of RAM version.
So my target was to find a server for less than 300$ having 32GB+ of RAM and 4x Quad-Core CPUs (16 in total). I finally found something matching my criterias there htpp://r.ebay.com/Dctsv8
The cons to concider before buying this server were:
- Close to no diskspace. (1x 73GB)
- The “rocket” noise it makes.
- The power consumption.
I decided to buy it because I have no use in having it running all the time so I will be able to keep it off most of the time for the sake of my electricity bill.
I made an offer and got it for 250$ including the shipping cost. It arrived in less than a week in a huge box filled with sprayed foam.
Warning: It is very heavy. Just lifting it out of the box to put it on a table can require a second pair of arms.
The 73GB disk will be good enough to store the operating system and its swap partition. But in order to have room for the VMs partitions I will need another disk. I don’t have too many requirements on this disk as it is just to start building the server and I can make it evolve with time. On eBay bought a 1TB Seagate disk that cost me 42$ and the hard drive caddy trays that are necessary for 35$.
The noise of the server is not too bad. The fans speed spike during the boot and then adapt to the temperature. I still decided to change them anyway after looking at an article of someone that made his dell poweredge quieter. The osbtacle when changing the fans in a Dell Poweredge server is the connectors: they are not standard. Followig the article advises I bought 4x Arctic 12cm PWM fans for 8$ a piece and got myself a soldering kit (made of those 3: 5.45$, 9$, 8$).
The colors of the fans cables are not the same as the connector. I found the following image online to match each cables pair:
There are 2 color schemes: blue-green-yellow-black and blue-yellow-red-black. The fans came with the first color scheme and the Dell connector with the second.
|Usage||1st color scheme||2nd color scheme|
Then it is just a matter of putting everything back in the server. Once started it displays an expected warning that the fans are too slow. If I get a chance I will update the firmware (maybe by following this article procedure) to change the speed threshold but it is not a priority.
|Dell Poweredge R900||250.00$||1||250.00$|
|1TB Seagate disk||42.00$||1||42.00$|
|Hard drive caddy trays||7.00$||5||35.00$|
|Arctic 12cm PWM fans||8.00$||4||32.00$|
|Heat Shrink Tubes pack||8.00$||1||8.00$|
|Server search||3 hours|
|Disk + trays search||30 minutes|
|Fans and material search||1 hour|
|Fans soldering and testing||3 hours|
|Total||10 hours 30 minutes|