Instability and hangs with USB-3 (UAS) external drives

[ZackPlonk]

Hi,

I've run into a very strange problem trying to use external USB-3 drives with my Macs.

The main setup is this:

* Mac Mini (2018) / MacOS Catalina 10.15.4
* External dual bay 2.5" HDD Enclosure IB-RD2253-U31 (ASM1352R Chipset)
* 2 SanDisk Plus SSD 1TB each

The disks are set up as an AppleRaid stripe set for maximum performance (there is backup happening to a NAS). The enclosure is hooked up to one of the USB-C ports of the Mac-Mini. The enclosure is also hooked up to an external power supply.

Things looked great initially. I was getting throughput around 500-650 MB/sec.

However, with continued used, I noticed that sometimes access to the volume would hang. Reconnecting the enclosure would solve this. I noticed that I could "force" the hangups by running "diskutil verifyVolume disk<n>" in a terminal. It would pass maybe 1 or 2 times and then it would hang and eventually report an error like this:

> ...
> Checking the fsroot tree
> error (oid 0x8d2) apfs_root: btn: dev_read_finish(2322209, 1): Input/output error
> fsroot tree is invalid
> The volume /dev/rdisk6 could not be verified completely
> File system check exit code is 0

When I would run it again, it would hang for a while and then report another error

> ...
> error: failed to read container superblock
> File system check exit code is 8
> Restoring the original state found as unmounted
> Error: -69845: File system verify or repair failed
> Underlying Error: 8

Reconnecting the enclosure would make it work again and the error could then be reproduced again.

I tried different (high quality) cables and different ports (USB-A, USB-C). I also tried going through a USB-3 hub. Always the same behavior. I tried to put different hard-drive (non-SSD) into the enclosure. Same behavior. I got the enclosure replaced. Same behavior (with both SSD and HDD on all ports). I then exchanged the enclosure to a different model using a different Chipset (JMS56x Series). Again I ran into similar problems.

I tried with a MacBookPro (2017) also running 10.15.4 and got the same behavior with all variations described above. I even tried an older MacBook that still had 10.14 on it. Same problems.

When I hook up any of the drive combinations with a USB-2 cable, everything is stable. Obviously, at a much lower speed (35-40 MB/sec) as would be expected with USB-2

Running ioreg in the terminal, I can see that when using USB-3 connection the volume is attached using IOUSBMassStorageUASDriver.

When using USB-2 connection it uses IOUSBMassStorageDriver (no UAS aka. USB attached SCSI)

Using a Lenovo Laptop running Windows-10, there seemed to be no such problems with both enclosures.

So in summary, whenever I hook up an external drive via USB-3 on any of these computers, the behavior is unreliable.

I'm at a bit of a loss as to what to make of this. Is anyone using a similar setup successfully or did anyone ever encounter similar problems? What else could be tried here? It looks like the UAS driver might just not be working correctly here - but I would expect such a thing to be noticed by many users pretty quickly.

Anyone has some idea what might be going on or what I might try to get this to run?

 

[hobowankenobi]

I have seen weirdness and instability with USB 3 on a variety of Macs...mostly on 2012 to about 2016 Macs. I never did any real investigating...but my hunch is certain USB buses or boards or firmware just don't play nice.

As an example, I have an external drive dock with both FW and USB 3. Same drive, same computer, USB is unstable, while FW (or TB with a FW adapter) is rock solid. Repeatable over several different machines, and changing drives and cables made no difference. That leaves the USB chipset in the device not playing nice with the USB chipset in the Mac.

I don't know any way to fix, beyond a driver/firmware patch for the board.

If it were OS specific, an update might fix. Same for Mac firmware. If the external USB chipset has a firmware update...that might do it. Without those, not sure what can be done.

 

[ZackPlonk]

At least for the ASMT Chip it doesn’t look like there is a firmware upgrade. I found some files but the software to upgrade the firmware isn’t something that is meant for end-users. You have to provide all kinds of funky parameters for and there’s no documentation. Vendor of the enclosure says they don’t have an upgrade. I haven’t checkt so much for the JMS chip... will search around a bit more.
I guess I’ll replace the rig with something Thunderbolt based. It’s a bit of a bummer as those enclosures are far more expensive then the USB-3 stuff which would be enough for me performance wise...

 

[hobowankenobi]

Ditto. It would be great it there was a source that showed which USB boards worked with Macs, and which had issues. I have not found one, so it is down to word of mouth.

And if my hunch is off, and it is not a USB chipset issue....I'm all ears.

 

[ZackPlonk]

My hunch is that it may be either chips that utilize UAS or at least those that support multiple drives or RAID.
If anyone is running a setup with a multi-bay enclosure via USB-3 successfully. I’d love to hear about the details