Board: SinoVoiop M4U (hostname=saran)
CPU: Allwinner R40 (quad core ARMv7 1.2GHz)
RAM: 2GiB DDR3
SSD: KINGSTON SA400S3 240 GB
SD-card: SB32G 32 GB
partition boot, vfat on sd-card (91M)
partition sys, Btrfs raid1 over ssd and sd-card (6.2G)
partition data, Btrfs single over ssd (5.2G)
partition innodb, ext4 over ssd (24G)

Switch: ST3105GS 5-port gigabit
Power Supply: 2.5A 5V switching LY2223 (about 1.3A used)
Router: Archer C2, via optic

Bacup workstation: (hostname=zirkon)
3 TB TOSHIBA DT01ACA3
3 TB TOSHIBA HDWD130
240GB SSD WDC WDS240G1G0B
data partition: Btrfs metadata raid1, data single over both harddrives

Remote control:
From pins 18 and 22 in open-drain mode are connected to Power and Reset on the B250 motherboard, parallel to usual case buttons buttons. Thus the Pi can wake the other computer up.

I am impressed, small is more powerful than I thought. Keeps costs down too.

Conan

what is Zirkon & Parlon?

Computers. Zirkon is the backup workstation and parlon is raspberry for misc automation.

New, much tidier, arrangement:

Old arrangement