OK, I think it may have to do with the odd number of data drives. If I create a raidz2 with 4 of the 5 disks, even with ashift=12, recordsize=128K, the performance in sequential single thread read is stellar. What’s not clear is why this doesn’t affect, or not as much, the 4x 8TB-drive raidz1.
Found the bit counter
Here’s the box test thread if you’re curious. 😊
I think I’ve seen this hypothesis too and it makes sense to me.
If I’m building a new AMD system today, I’d look for a board that exposes more of the chipset-provided USB ports. Otherwise I’d budget for a high quality 4-port PCIe USB controller, if I’m planning to rely a lot on USB on that system.
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.
I’ve been on the USB train since 2019.
You’re exactly right, you gotta get devices with good USB-to-SATA chipsets, and you gotta keep them cool.
I’ve been using a mix of WD Elements, WD MyBook and StarTech/Vantec enclosures (ASM1351). I’ve had to cool all the chipsets on WD because they like bolt the PCBs straight to the drive so it heats up from it.
From all my testing I’ve discovered that:
I like this box in particular because it uses a very straightforward design. It’s got 4x ASM235CM with cooling connected to a VIA hub. It’s got a built-in power supply, fan, it even comes with good cables. It fixes a lot of the system variables to known good values. You’re left with connecting it to a good USB host controller.
I thought about it, but it typically requires extra PCIe cards that I can’t rely on as there’s no space in one of the machines and no PCIe slots in the other. That’s why I did a careful search till I stumbled upon this particular enclosure and then I tested one with ZFS for over a week before buying the rest.
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.
Thanks for the warning ⚠️🙏
This isn’t my first rodeo with ZFS on USB. I’ve been running USB for a few years now. Recently I ran this particular box through a battery of tests and I’m reasonably confident that with my particular set of hardware it’ll be fine. It passed everything I threw at it, once connected to a good port on my machine. But you’re generally right and as you can see I discussed that in the testing thread, and I encountered some issues that I managed to solve. If you think I’ve missed something specific - let me know! 😊
That was the cheapest option. 🤭
Two machines. A main server/workstation and a small off-site backup machine that runs the same services but hass less compute and RAM.
Multilayer recording sounds like it would require read-rewrite similar to how SMR works. Still perhaps we’d be okay with that for the dramatic capacity increase.
And now it no longer shows up.
Quite possibly. That said the one I linked is CUI, not a noname. It’s even got an MTBF of 300K hours in its datasheet. There are cheaper ones. 😅 And more expensive ones.
It can’t because birds are not real.
I see a number of dual-output PSUs on Mouser that will probably fit well if this goes. For example.
Yeah, I googled that IC, no hits. 😂
git merge --no-ff
Yes, yes I would use ZFS if I had only one file on my disk.