Catalina - External Hard Drives repeatedly ejected without cause.

Mine is an OWC hardware raid box over tb2, a pair of HGST 4tb nas drives, no 3rd party drivers. This approach with WD 3rd party drivers would have no bearing on my device. To reiterate, I’ve used the same external drive box with each macOS release since 2013, and Catalina is the first release where this problem occurs. I installed the Keep Drive Spinning app A week ago, and have not yet experienced a disconnect yet. It usually happened with heavy activity ops, like a big copy, or starting a Linux vm in parallels or VMware fusion, but the KDS app appears to have helped.

Looks like I spoke too soon when I posted yesterday.... Having had my external drives connected via USB with no problems for a week or so, this morning the machine had shut down with a(another) kernel panic.

It occurred to me that the only thing that had changed since yesterday was that I set up the (new) MacBook Pro to back up using Backblaze, so wonder if the file transfers that triggered had caused the problem.... Will keep an eye on it and report back

Hi H-E-J,

As you might have read, I also suffered a random unmounting after installing the 10.15.5 update. For me, it turned out the hurdle to fixing the drive is the way macOS automatically kicks off a repair process without communicating this in any way via the graphical interface. It seems that when a drive is determined to require filesystem repairs, the OS silently initiates fsck_hfs (filesystem check for HFS+), which must run its course before the drive can be mounted. I killed off the fsck_hfs process using the Terminal and ran Disk Utility on the drive so that I could monitor the progress of the repair process. After many hours, the filesystem was repaired and the drive is working as expected. Fortunately, I suffered no data loss. If you are indeed encountering the same issue, I suppose you could just let the silently initiated fsck run until it fixes the filesystem damage that the update caused, but there is no feedback provided while it is running.

https://matthovey.wordpress.com/2013/06/17/resurrecting-a-time-machine/

Apple, this issue is the result of two organizational failures.

1. Please fix your QA process. Prioritize the quality of releases over their frequency. Catalina has been — by far — the buggiest macOS release I have used in years. The marketing people may crave a yearly release for their purposes, but it leads to technical debt and bugs that cause serious disruptions to users.
2. Provide a user-centered interface when the system determines that a drive needs filesystem repairs. Less technically inclined users need to know that their drive experienced some damage and that the system is attempting to fix it. Silently initiating a process that may require upwards of a dozen hours can leave people with the impression that the drive must be erased and reformatted.

As an update, I misdiagnosed the fix for this. In the midst of trying screen savers off and other SW related issues, I also moved my external SSD to an available USB port on my Thunderbolt Display. So MacPro trashcan model, USB's under Catalina display the problem. I will note that it works perfectly fine on the MacBook Pro (2013) USD ports running Catalina, but not on the MacPro. Once I moved the cable to the Thunderbolt USB port, the signal is routed via Thunderbolt 2 into the computer, by-passing the USB ports them selves on the MacPro. This works perfectly fine and has been working since my last post.

After 6 month of pain and very little work I know requested a refund for my 2019 MacPro and will be purchasing the last iMac which I can still run with Mojave on.... Will see in a year once the ARM machines are out what to do but after 25 years of apple I'm at a point to moving to windows and Davinci resolve

I've connected the Lacie drive to a MacBook running Mohave and it's running perfectly fine. I bought the drive from Jigsaw24 in the UK. They have suggested reformatting the drive. Even though the drive is working on the MacBook, it may well be it will work with Catalina if I reformat it on my iMac running Catalina. However I'm loathed to do this. If it is an Apple issue they are hopefully going to fix soon, I may just wait on for that fix.

Hi Everyone - just an update to this very long ongoing issue..

All my usb drives work fine, they always have, with Mojave..

My thunderbolt 1 Western Digital drive also worked fined with Mojave... As did all of my apps, software, extensions, iPhone backup, podcast backup etc etc

Since updating to Catalina, and ONLY since updating to Catalina.... my usb drives all still work fine, most of my apps do not, come back iTunes all is forgiven, podcasts & iPhone backups are all over the shop, 32 bit apps don't work at all ( was expected though )

But the Thunderbolt 1 drive became absolutely unusable - staying connected for all of 5 minutes, as soon I started to access data, it would eject, transfer anything, eject, do anything that the drive was actually designed & manufactured for - eject..

Thanks (Cr)Apple....

However - the fix :- I bought a new genuine thunderbolt 1 cable, and it has been fine ever since.... yet again, it's the same as Apple did with iPhones, if you hooked up your iPhone to a mac, using a non-genuine apple cable, it ruined the cable, or the iPhone connection to the mac, if you used a non-genuine battery in your iPhone, and repaired it yourself ( being an electronics technician ) instead of paying vast sums of cash to a genuine repair shop, magically the latest software update would sense the imposter battery and obliterate the phone, turning it into an expensive paperweight/doorstop.

A bit like Microsoft sending out 'pings' to check for authentic versions of windows installs - if you were running a corrupt copy, magically your pc would crash & die.

Not to mention in-built obsolescence in flat screen tv's and the like programmed into the software......

Anyway - New cable, been fine ever since :-D

that is bad mate, to be honest I lost all faith in apple I returned my 6 month old 2019 MacPro for a refund as with the disconnect issues I could not see me having 12 invested in a machine. I now bough for less the 1/2 the 2020 iMac 5k and after playing around with a few docs and set ups as well as selling all my USB c Drobo's I now seem to have it running without disconnects with 2 x OWC Thunderbolt 4Disk Raid's one Drobo D8 and one Drobo 5D3. It's a fragile peace and it now always shut my machine down at night as the disconnect for me mainly happens when machine goes to sleep. I'm now contemplating if I move to Windows or wait for the new ARM Macs and see it it's solves it. After 20 years on the Apple Platform is hard to see ho Apple is going down the drain.

I just got the new OWC Envoy Express TB3 NVMe enclosure which was released in October 2020. It's supposedly the "first Thunderbolt3-certified universal NVMe enclosure." I installed a brand new ADATA XPG SX8200 Pro 2TB NVMe drive into it.

I have a 2019 iMac Retina 5K 27" on Catalina 10.15.7 which I've been booting and running from an external USB3 2TB SSD for a year and I've had zero disconnects during that time, even with heavy FinalCut i/o. Tonight I booted from the Fusion drive and ran a Carbon Copy Cloner job to image my USB3 drive to the TB3 drive. After cloning a few hundred gigs of data, the TB3 volume disconnects and both the application and MacOS throw errors. The drive is unreadable in any of my macs once it's in this state, and it's not even enumerated via "diskutil list." The only way to even make it visible again it is to disassemble the enclosure, remove the NVMe, plug it into the secondary slot on the motherboard of my Windows PC, run a "diskpart clean", and then reinstall it into the OWC enclosure. I've been through that entire process twice, always with the same results. All data is lost with that method, of course. Very disappointing that I can't even do anything at the command line.

First thing I would do is replace the cables.

clean my Mac X has caused plenty of problems by itself.

These are separately plugged to the power. Wondering if maybe one of my USB ports is causing issues.

What OS are you on, & if it's a Time Machine volume on later MacOS version you cannot disable Spotlight on it.

https://x704.net/bbs/viewtopic.php?f=6&t=8867&p=116733#p116733

Try Drive DX.

Great to hear, thanks! :)