Yes, it can serve as a home server using Add2PSU and PicoPSU to supply power to external SATA drives and case fans.
Yes, it can serve as a home server using Add2PSU and PicoPSU to supply power to external SATA drives and case fans.
I came across an article discussing how to operate a Mac Mini as a low-power idle and efficient home server with external SATA storage.
The piece explains that using Thunderbolt connectors with M.2 enclosures and M.2 to SATA adapter cards works, though it may feel somewhat sluggish. However, things will become even more problematic at lower power levels. (Important note: for a home server setup, RAID5 would be necessary, and the only viable option on macOS is OWC's SoftRAID.) For powering the SATA drives, Michael employs a large dedicated PSU, which I think is excessive.
Previously, I hadn't seriously considered using a Mac Mini as a server. But with the advancements in Docker on aarch64—including Rosetta support and native virtualization—and the improved stability of SoftRAID (now even included natively in macOS), plus the Mac Mini's strong performance with local LLMs, I've started to explore this idea more.
You could theoretically set up a 2U server chassis, such as one from SilverStone, mount the Mac Mini, use 5.25'' SATA cages (like those from Icy Dock) for storage, add a few case fans, and it should work. Just need to connect everything properly.
Michael has already addressed the data connections via Thunderbolt to SATA through M.2 adapters. My main concern is the power configuration. In his configuration, an ATX jumper is used, which would keep the storage powered even when the Mac Mini is off. I haven't researched this extensively yet, but it seems like a practical approach.
I plan to add a passive USB-C to USB Type A dock to one of the two USB4 ports on the front of the Mac Mini.
This would allow me to connect a USB4 port to the front of a 2U chassis, which could then serve as a hub for an external Time Machine drive.
I’d also connect the other USB Type A ports on the hub to the front USB ports of the 2U chassis, leaving the Mini’s remaining USB4 port unused—potentially usable for an external Time Machine drive.
On the passive hub side, I would plug in a USB Type A to Molex adapter cable.
This cable would feed into the Molex input of an Add2PSU.
For powering the PSU, I’d opt for a PicoPSU rather than a full ATX unit, since I only need to supply SATA (mostly SSDs) and a few fans. The PicoPSU connects to the Add2PSU via its 24-pin ATX interface.
I estimate that 90W would suffice for one HDD, up to six SATA SSDs (maximum nine), plus up to three PWM fans.
Regarding fans, I’d remove the small 12V ATX 4-pin connector from the PicoPSU and route the wires through a thermostat PWM controller to power both the controller and fans.
For SATA power, I’d need splitter cables to connect multiple SATA drives (all SSDs except one) to the PicoPSU’s outputs.
PATA connections would go to 5x SATA ports, while SATA would handle the SSDs. The 5.25'' SATA cages would likely include their own fans or be powered via the same SATA connection. A 5-way splitter might be excessive, but it would be safe.
Overall, this setup is quite complex, but it could work if executed correctly. Does this approach seem reasonable to you? Please let me know if I've misunderstood anything.
It would certainly be feasible to skip all the issues and opt for a Launch Daemon that executes a minimal shell script during the Mac Mini startup. This script would communicate with a smart plug, which would then activate to supply power to the PicoPSU and the entire storage system.
However, this approach would keep the storage powered even after the Mac Mini powers down. In macOS, there exists an option called "logout hooks," but it’s unlikely you could utilize it for tasks requiring network communication like data transmission. Additionally, it appears Apple has discontinued this logout hook feature in the latest macOS versions.
Wouldn't it be simpler to use only the Mac Mini and a self-powered four-bay enclosure?
Consent given for setting up a 4-bay enclosure, allowing the mac to handle it while keeping other tasks minimal.
Yes, these are all conventional DAS configurations, which are already discussed in Michael's article with their advantages and disadvantages. Mostly negative points were highlighted, prompting him to develop his own approach, which forms the basis of my inquiry. Referring back to Michael's concept, the setup involves connecting two Thunderbolt ports to M.2 enclosures at the rear of the Mini, removing the top covers, installing an M.2 drive on each SATA adapter card, and linking them to the backplane of a SATA enclosure filled mainly with SSDs—using either SATA cables or SFF8087-to-SATA adapters depending on the M.2 cards, backplane, and enclosure type.
To summarize, my main concern now is determining the correct power configuration, particularly ensuring that the SATA system, powered by a PicoPSU, activates automatically when the Mac Mini starts up and shuts down automatically upon shutdown. My proposed method is: drawing power from the Mini's front USB-C port, routing it through a passive USB-C to 4xUSB Type A hub, connecting to a USB Type-A to Molex adapter, then feeding into an Add2PSU, which activates the PicoPSU via a 24-pin ATX connector. This powers the SATA setup via splitter cables to the drives or backplane, and supplies additional 12V to the fan controller.
In short, here are my main concerns:
(1) Can the 5V from the Mac Mini’s front USB port pass through the passive hub using the adapter cable to reach the USB-Type-A-to-Molex connection?
(2) Is this enough to send an on/off signal to the Add2PSU via the 24-pin connector?
(3) Will a 90W PicoPSU provide enough power for up to nine SATA SSDs, one SATA HDD, and fans (through both SATA and PATA connectors), or is it limited by the storage setup?
(4) Can the 12V connector on the PicoPSU supply power when connected to the thermostat controller, and can it run six fans in addition to the storage devices?
There exists a method to partially bypass the logout hook deprecation by using events sent internally by macOS. An application named EventScripts can execute shell scripts when specific events occur, such as "Computer will shutdown." This approach seems incompatible with the Unix shutdown command, though it may function for shutdowns triggered through the UI or via osascript. This allows running a script that uses diskutil unmountDisk to detach storage, applying force to prevent errors, and then sending a network command to a smart plug—like a CloudFree plug—to cut power to the storage. After a restart, a LaunchDaemon could reverse this action, turning power back on and mounting the storage if needed. The current shutdown procedure remains ineffective if the Mac shuts down unpredictably, but it offers at least partial relief. It also doesn’t support reboots, though leaving the storage active might be acceptable in that scenario.