This seems to be a limitation of Intel host controllers. The USB 2.0 specification (including 12 Mbps Full Speed) allows for up to 127 devices. Each of those devices can have up to 16 IN and 16 OUT endpoints, c.f. https://www.usbmadesimple.co.uk/ums_3.htm Depending on how you count, that would be a maximum of 2k to 4k endpoints in total. I guess Intel thought it wasn’t worthwhile supporting that many endpoints.

Some quick searching turned up this post that claims that USB3 controllers often support up to 254 endpoints (in total). https://www.cambrionix.com/a-quick-guide-to-usb-endpoint-limitations/ Other posters have also said that AMD appears to have higher limits. You could also consider adding more USB root hubs to your system (with PCIe cards).

Unfotunately, I can help you with that. The machine is not running any VMs.

It’s possible, but you should be able to see it quite easily. In my case, the CPU utilization was very low, so the same test should also not be CPU-bottlenecked on your system.

I’m seeing very similar speeds on my two-HDD RAID1. The computer has an AMD 8500G CPU but the load from ZFS is minimal. Reading / writing a 50GB /dev/urandom file (larger than the cache) gives me:

• 169 MB/s write
• 254 MB/s read

What’s your setup?

With version 2.3 (currently in RC), ZFS will at least support RAIDZ expansion. That should already help a lot for a NAS usecase.

That system also sounds a lot more capable than mine. How did you end up with 25 VMs?

I’m running it in a regular mATX case (Node 804) but I think you can also get AM5 motherboards in rack-mount cases.

Perhaps my recent NAS/home server build can serve as a bit of an inspiration for you:

• AMD Ryzen 8500G (8 cores, much more powerful than your two CPUs, with iGPU)
• Standard B650 mainboard, 32 GB RAM
• 2 x used 10 TB HDDs in a ZFS pool (mainboard has 4x SATA ports)
• Debian Bookworm with Docker containers for applications (containers should be more efficient than VMs).
• Average power consumption of 19W. Usually cooled passively.

I don’t think it’s more efficient to separate processing and storage so I’d only go for that if you want to play around with a cluster. I would also avoid SD cards as a root FS, as they tend to die early and catastrophically.

It’s an Apple Silicon Mac Mini. Do you have a particular reason to think the new one is less efficient?

I do think it can achieve that while waiting for network packets (see e.g. https://www.anandtech.com/show/16252/mac-mini-apple-m1-tested).

But in terms of money savings it would rarely make sense, as you need to make it back during the time you run the system. If we assume 6 years lifetime then it would only make sense to pay $120 more. But yes, I’d also go for a system that runs regular Linux :)

I don’t have one (and I don’t want one), but Anandtech measured the M1 version at 4.2W in idle. https://www.anandtech.com/show/16252/mac-mini-apple-m1-tested I think you can also get that from other Mini PCs (e.g. NUCs).

I would disagree with idle power not being important for a home server. Most of the time, your system will be doing very little and wait for something to happen. I also don’t think a typical server has a display attached. Wolfang explains this quite well: https://youtu.be/Ppo6C_JhDHM?t=94&si=zyjEKNX8yA51uNSf

I don’t have a Mac Mini, but for always-on systems, the idle power consumption can become quite significant.

• Gaming PCs can consume up to 100W (876 kWh / year).
• My AMD B650 NAS consumes about 17W in idle (150 kWh / year).
• A NUC / Mac Mini can idle as low as 5W (44 kWh / year).

If you pay 0.30$/kWh, running your old 100W gaming PC all the time would cost you 263$ per year. My NAS is 45$ per year…

It also depends on what you need/want from the machine. The Mac Mini doesn’t have any HDDs and can’t run a regular Linux distro, for example.

No, they’re almost entirely unrelated. Almost all CPUs will idle close to 0 W (with correctly working drivers). The main idle power contribution comes from the mainboard and other devices (e.g. disks). The Mini PCs you mentioned should have a very low total idle power, probably below 10W.

Check out Wolfgang on YouTube, he has some great videos on the topic: https://youtu.be/Ppo6C_JhDHM

I’ve also recently built my own NAS and I’ve gone through similar considerations. One of my mayor decisions was not to use btrfs because it’s not recommended for Raid Z1/Raid 5. With that, I landed on ZFS and TrueNAS Scale. Note that RAID expansion should be landing in both very soon.

Things with TrueNAS were pretty easy, very quick, and everything worked nicely. However, I noticed that it was constantly accessing the disks and preventing them from spinning down. I really wanted to keep the power consumption low (<20 W idle), so I eventually decided to just go with Vanilla Debian + ZFS. I can recommend that if you want to tinker with things yourself. Otherwise, I’d recommend TrueNAS Scale.

As for migration, you might be able to create a degraded pool initially, copy over the data, and add the parity disk last. Raid expansion would ofc also help there…

One way to do it is have a small Python (or any other scripting language really) script that performs text replacements in the Latex source file. This is much easier in Latex because it’s plain text. I don’t know of a solution that doesn’t involve writing your own code (apart from LO/Word serial letters).

Is using Latex an option? I’ve done that and it works quite nicely. You can easily populate a template e.g. using Python.