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.
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! 😊
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.
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’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:
ASM1351 and ASM235CM are generally problem-free, but the former needs passive cooling if close to a disk. A small heatsink adhered with standard double-sided heat conductive tape is good enough.
Host controllers matter too. Intel is generally problem-free. So is VIA. AMD has some issues on the CPU side on some models which are still not fully solved.
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.
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 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.
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.
Recommendations for Hardware for Physical Media/Jellyfin Server
Initial Thoughts...
Splosion (lemmy.ca)
Slow sequential single file reads on ZFS
I built a 5x 16TB RAIDz2, filled it with data, then I discovered the following....
Breaking Down the Housing Policy Blitz | #onpoli (youtu.be)
I wasn’t aware Steve Paikin and John McGrath had a podcast on Ontario politics. I like it!
The beatings will continue until morale improves (lemmy.world)
politico.com/…/pay-raises-smaller-prices-workers-…
Just a bunch of enclosures (JBOE) (lemmy.ca)
120TB hard drives are coming, thanks to new Seagate tech (www.pcgamesn.com)
me too (mander.xyz)
OWC Mercury Elite Pro Quad as USB Direct Attached Storage (DAS) for ZFS
Why...