Coolermaster case on the right

Coolermaster case on the right

Φόβος (phobos) is the name of my NAS, backup and home server. It's the successor to a Mac mini G4 and the (ultimately abandoned) Thecus n2100. It's now on its second mainboard, notes about the first one are at J1900N-D3V.

It's a small (ish) size, passively-cooled PC that I leave on 24/7 and performs various duties for me, most importantly being a large archive storage space and a separate backup space.


Power consumption


  • SoC: 10W (Intel TDP), some people experiencing draw of about 14W idle with one SSD connected

I plan to do some power draw measurements in the near future.

Some notes

The Coolermaster case is high-quality. It's much bigger than I'd like, but is the smallest case I could find at the time. It's about the same size as a HP Microserver (which I was continually recommended when I re-specced this machine) and there's at least growing room.

Front/side USB port provblems

The front (side) USB ports are weird. They are mounted upside down in the case. With two different mainboards I've had a succession of problems using them for removable storage.


Debian GNU/Linux for the operating system. I backup via rdiff-backup.

I don't use RAID (which is not backup).

Remote decryption

I use full-disk encryption which necessitates supplying a passphrase when the machine is booted. Since this is a headless box, some additional work is needed to permit supplying this passphrase over the network. Luckily most of the work is done already by installing the dropbear Debian package and reconfiguring keys and authorized_keys files in /etc/initramfs-tools afterwards. This means I can SSH into the pre-boot environment. From there, I just need to run cryptroot-unlock and supply the decryption passphrase.




I wanted to add a means of notifying me of events on the machine. I bought a Blinkstick Nano, a tiny USB stick with an LED on each side. I've hooked calls to change the light colour into the success/failure paths for the systemd jobs that drive my backups. Further details here: 1, 2, 3.

The light defaults to off. When an interactive job is in progress, it turns on and blue. When the job completes, the light changes to either green or red depending on success or failure. Green means I am safe to remove the drive, in the case of external drives.

When a non-interactive, scheduled job fails, the light turns red. I usually notice this next morning.


comment 1
Have you tried making a VGA dummy plug to fool the board into thinking a monitor is attached?
Comment by Guest,
comment 2
Hi - I have the parts for a dummy vga plug on the way from Hong Kong but I haven't received or assembled them. Someone else has told me that the board doesn't complain about displays for them if they turn on CSM emulation mode, so I will try that too.
comment 3
Do you run this fully passively cooled, ie. no fans at all? Is this ok with the HDDs? What are their temps and how long have they been running like that? Were there any failures of any parts since creating Phobos?
Comment by avisitor,
comment 4
Answering what I can right now: no fans, no failures. Disk temperatures a steady figure below their max operating temperature according to their specifications; I can’t remember the number off hand but I think they’re in the low 40s °C. This has been running for about 3 years now.
comment 5

Both disks are currently at around 35°C. I think this is pretty constant, but it might depend on the season of the year. I've just put in place an additional monitoring step so I can track it better going forward.

comment 6

Can you post SMART data of these HDDs?

I'm trying to decide currently whether to go for this Cooler Master case or for Chieftec IX-01B/IX-03B. The latter is much smaller (although the CM isn't big either and shouldn't be a problem to move around) and fit for passive cooling, but hold only one HDD, so max 8-10TB right now for me for the whole unit, that may very well be enough for me up to the point where SSDs are cheap enough to use them for this purpose. Putting fans in that Chieftec is not great, because it can hold only 50mm ones and these seem to be louder.

Comment by avisitor,