There are issues with USB from a compatibility standpoint. I think its mainly a factor of the ubiquity of it, there are SO many poor controller chips out there, even when you buy seemingly reputable hubs/drive cases. Its hard to find a good one sometimes. I did, however, stumble upon a gem early on, it was a 3.5" usb drive case from BestBuy which has since been discontinued(because it was good). Never in 15 years has any of the half dozen ones i got dropped from thier system. This is more than i could say about alot of pricey stuff on amazon sadly. Its typically manifested as a random loss in connectivity to the system.

Similarly, heres a very low power writeup I did for using 2.5" drives with a dedicated power hub/splitter. http://www.jofla.net/?p=00000106#00000106 This will still have issues if the mains lines sag (a pole goes down somewhere), but you can fix it with a reboot remotely. Other than that it works great.

This was/is definitely a labor of love, primarily as I've come from a time when all you could get for a server were huge boxes idling at 50 watts, so i felt guilty of all the power I used to consume.

> I also want to set up a NAS on a mini-PC with some sort of attached external storage, but I haven't been able to get past this blocker

You could also buy a PCIe to multiport SATA (RAID) card, but you'll also need a bigger[1] NAS-like case[2] to house the hard drives and multiple power cables for the drives

1. Depending on how mini your PC is and how many drives you want to attach to it

2. I have noticed any case that's sufficiently NAS-like (hotswap trays) is sold at a premium.

> Isn't running a NAS on top of USB storage very strongly discouraged? TrueNAS cautions against it.

You're right, and I don't recommend USB as the only backup solution. I an old eSATA enclosure - not sure if that's an improvement over plain USB - as a secondary backup and keep the device on long enough to complete)

You aren’t wrong. USB is not a good way to do this.