I have decided to build a bare metal Kubernetes K3s cluster using a number of Lenovo M92p Tiny desktop machines as the cluster nodes.
These machines really are small
I had previously bought a Lenovo M93p Tiny for use as a dedicated Minecraft server for my kids and really liked the size as well as its low power draw and the fact that it was silent.
My Dell R210 ii server is certainly not quiet and even sat in the loft area still generates a decent amount of noise, it also has a 250W PSU that draws around 44W at idle and over 105 under load.
It is more than capable of running the dozen or so VMs I have on it, but struggles if any of them actually have any real load. It has 32GB of RAM and an Intel Xeon E3-1280 3.5GHz CPU with 8 threads and a benchmark rating of 5510 (1780 for single thread).
I negotiated a good deal on some bare Lenovo M92p Tiny machines (no RAM, no hard disk, no PSU) at £40.00 each for 8 of them, each with an Intel i5-3470T 2.9GHz CPU with 4 threads and a benchmark rating of 2949 (1786 for single thread). These use a 65W PSU and around 12W at idle, 39W under load, so potentially higher power usage across all 8 servers, but that has yet to be seen.
The intention is to use 3 as master nodes running the etcd database and 5 as worker nodes.
I found a separate deal for 7 PSUs for £32.00 (just need to find an 8th one) and then bought a bunch of 8Gb SODIMM modules for £6.00 each in another deal, this will allow me to have the maximum supported 16GB RAM in all 8 servers.
I purchased a 10 x 0.5m C5 to C14 power leads (male clover leaf/Mickey Mouse to female kettle) along with another 8 way PDU and a 1U shelf from CPC for a total of £67.31.
I already had enough 2.5″ hard disks of various sizes, (160GB for the master nodes, 400/500GB for the worker nodes) so did not have to buy any of these.
I also bought 8 Fueran Display Port EDID adapters from Amazon (a 6 pack and a 2 pack) which worked out at about £6.50 each.
The reason for purchasing the ‘p’ version of the Lenovo M92p Tiny is because the ‘p’ versions also have Intel vPro technology built into the motherboard that allows remote access over the Lan interface even when the server OS is down. The EDID adapters fool the server into thinking it actually has a display attached.
The intention is to have all 8 servers as well as my Hitron router sit on the same shelf at the top of my rack
There should be more than enough space for all of these items plus my Hive hub and a PoE injector for my outside switch.
The Lenovo M92p Tiny servers all came with trays for the internal hard drives, but no screws. Fortunately I have loads of screws left over from previous PC installs over the years so finding a bunch of suitable ones was not an issue.
Total cost for this project is about £350.00 which is possibly slightly less than what I paid in total for the Dell R210 ii (32GB 8 threads) but will have 128GB RAM, 32 threads and several TB of internal storage and plenty of redundancy.