2024 Homeserver

I was looking for a low energy home server setup to run my very modest 24x7 load: a backup target, a wiki, some tooling around my solar roof, media serving - the usual stuff.

My requirements are:

• low idle power consumption: < 20 Watts on the wall
• can run containers
• I want to reuse the components that I hve: a random power cupply, some disks, the chassis etc.
• easy, robust, fun

The Search

Searching for a configuration was harder than I expected: It’s not easy to predict the power consumption of some configuration before you get your hands on it.

I was considering consumer configuration around Intel I5’s or Ryzen 5, but I wasn’t sure about the idle power consumption. I did not consider a Raspberry Pi. Rappberries are very nice devices but I wanted to avoid the trouble around the SD card as boot medium.

The NUC-like devices were tempting, but they can’t house my old 3.5" disks.

Here are some resources that I found useful:

• Busting 8 Common Homelab Power Efficiency Myths
• The Perfect Home Server 2023
• 7 watts idle on Intel 12th/13th gen: the foundation for building a low power server/NAS

My Choice: a N5105 board with Proxmox

I found this board on Amazon for 140 Euros earlier this year, directly shipped from China with 3 weeks delivery time. In between the same board was also avaialbe for 10 Euros more but shorter delivery time. Currently it’s out of stock.

It is a Mini ATX board with

• an Intel N5105 Celeron CPU
• 4 x 2.5 GBit NICs
• 6 x Sata drives
• 2 x M.2 slots
• 2 RAM slots

It came with AMI Bios from March 2023 - and I would be surprised if there is ever an update.

$ sudo dmidecode
# dmidecode 3.4
Getting SMBIOS data from sysfs.
SMBIOS 3.3.0 present.
Table at 0x78D77000.

Handle 0x0000, DMI type 0, 26 bytes
BIOS Information
        Vendor: American Megatrends International, LLC.
        Version: 5.19
        Release Date: 03/28/2023
...

hwinfo says it has

• a 4 core Intel(R) Celeron(R) N5105 @ 2.00GHz, 2800 MHz and
• the NICs are Intel Ethernet controller supporting up to 2500baseT/Full, but I am only running 1000Mb/s.

I put a bunch of my existing spinning disks in and initial power consumption was a bit higher than I expected, around 25-40 Watts, measured at the wall. Once I was able to spin down the and tuned it with powertop, then I got it down to ca 15 Watts.

I am running proxmox on this machine and it was a bit difficult to get the disks to spin down. My initial setup was ext4 as filesystem. That makes proxmox polling the disks for some status information so frequent that no disk ever went to sleep. So, I converted the disks to zfs and proxmox handles those disks differntly with regard to disk polling. Some simple spindown_time = 200 for each disk and now the disks are spinning down:

$ sudo smartctl -i -n standby /dev/sdb
smartctl 7.3 2022-02-28 r5338 [x86_64-linux-6.5.11-7-pve] (local build)
Copyright (C) 2002-22, Bruce Allen, Christian Franke, www.smartmontools.org

Device is in STANDBY mode, exit(2)

powertop --auto-tune froze the machine, I had to omit touching the Ethernet Controller I226-V and that how I got to this idle measurements:

I am running the machine with 16GB of DDR4 RAM. I also tried 32GB but the machine was crash-looping and I didn’t had the necessary patience to figure out, if there is a way to use more than 16GB.

Summary

I am really happy with the setup: it runs stable for 2 weeks now, has the expected low power consumption on idle and is powerful enough to support my very modest load. A single proxmox node… is that really enough from an availabilty perspective? If I ever have to replace the board then the delivery time of a couple of weeks … I am not sure what to do next.