Bus issues usually. Having a disk (or 4) drop out of a ZFS filesystem regularly isn’t a good time.
If you can find a combination of enclosure, driver/firmware and USB port that provides you with a reliable connection to the drive then USB is just another storage bus. It’s generally not recommended because that combination (enclosure, chipset, firmware, driver, port) is so variable from situation to situation but if you know how to address the pitfalls it can usually work fine.
You want ASMedia ASM1351 (heatsinked) or ASM235CM on the device side 🥹
This box has 4x ASM235CM and from the testing I’ve conducted over the last week it seems rock solid, so long as it’s not connected to the Ryzen’s built-in USB controller. It’s been flawless on the B350 chipset’s USB controller.
so long as it’s not connected to the Ryzen’s built-in USB controller.
Could you elaborate? Do you happen to have any theories as to why?
I have a zen 3 chip and while I’m not planning anything like this, I’m just curious.
I don’t know, but I’d guess the buffered chipset controller has more stability during certain power state transitions.
This article provides some context. Now I do have the latest firmware which should have these fixes but they don’t seem to be foolproof. I’ve seen reports around the web that the firmware improves things but doesn’t completely eliminate them.
If you’ve seen devices disconnecting and reconnecting on occasion, it could be it.
