Catalina - External Hard Drives repeatedly ejected without cause.

Oh, I am so glad (well I guess not really... misery love company?) to see I am not the only one having this problem. I have posted about it elsewhere in these forums.

I updated to Catalina and random shutdowns ensued only when the Thunderbolt (1) drives I used for TM backups were mounted. Tried various fixes, clean install, fresh backups, many calls to Apple Support... eventually bringing the iMac into my Apple Service Provider, along with the external hard drives I used for backups, both of which were connected via the Thunderbolt 1 interface (one of them via a Thunderbolt to Firewire adapter). They rebuilt (as it were... cleaned up) the iMac Fusion Drive, redid the clean install, and tested both external hard drives, reformatting one of them (at some cost). They could find no hardware issues with the iMac.

Problem persisted with random shutdowns when external hard drives were mounted. So replaced both with new USB external drives... no more shutdowns. Griffin replaced the G-Drive Pro Thunderbolt along with a new Thunderbolt cable under warranty. I retired the other older WD drive (firewire connected via a Thunderbolt adapter). But problem persists.

Then I did another clean reinstall, migrating only User Data over (no Applications or Network Settings) to see if this would fix it. Problem persists only when the Griffin G-Drive Pro Thunderbolt is mounted, random crashes (shutdowns), not when the two USB external drives are mounted.

There is no Firmware update for the G-Drive that I could find (oh, and I reset the SMC and NVRAM... not the cable, but it has happened with two separate cables... could they both be bad?).

Apple says it must be a hardware issue since I've done all I can, but I have a feeling Catalina is not playing nice with the Thunderbolt interface or just the G drive architecture somehow. The problem only surfaced with Catalina.

Love to know if anyone else has gotten any info on this.

Dear DanG77

Just to say in addition to my 8TB suffering from this issue, my GTech 4TB drive has now also had the same problem. The new drives I installed continue to perform well.

However I know have 12TB of unusable external storage. Luckily my back up regime has worked. I have applied EVERY recommended fix to no avail. It would be 'nice' at least if one of the suppliers would step up to the plate and provided a solution.

Kind regards

Peter

If anyone figures out a fix, I would love to know. Anytime I have the G-drive Pro Thunderbolt (Thunderbolt 1 in my case) connected, I can get random shutdowns. Never happens with just USB drives mounted. I have tried every fix known to Apple to no avail. After the last clean install, I was able to backup to the G-drive, left for a couple hours, came back and found the random shutdown had occurred. I tried clicking on the G-drive icon to see its contents. got a spinning beach ball and then the dreaded black screen. I finally emailed Griffin support. Love to get a fix... these drives are not inexpensive, and to have them basically unreliable with Catalina is just bizarre and frustrating.

You don't need to revert the computer. You can install it on an external drive and boot with that drive. for what it is worth, part of my backup system is a current clone of my internal drive. When I upgrade to a new OS I keep that clone so I can boot with the older OS should I discover a software or hardware issue associated with the new OS.

Yes I understand. However using a different machine will be good practice as it will eliminate that possibility that other hardware or software issues (none that I know of) are causing the problem.

I will report back - may be a couple of weeks.

Regards

Just a quick update on my situation. I have tried reconnecting my older WD Firewire drive which is connected to my iMac via an Apple Firewire> Thunderbolt adapter (my iMac has two Thunderbolt 1 ports). So far no random shutdowns. On Griffin's advice I have connected the G-Drive Pro to my MacBook Pro running Mojave (too old for Catalina). I am using it as a duplicate TM backup on the MacBook. I will see if any problem shows up, but I don't think it will.

I have a strong suspicion that this is a problem to do with Catalina and the G-Drive Pro Thunderbolt (and other related drives) in particular based on the timing of the problem's first occurrence and all the trouble shooting I have done. It may only happen on Mac's with Fusion Drives as well (which I have) based on some of the issues I've seen reported elsewhere in these forums (MT Mapping, FS Root).

I'm having the same problem with a series of Lacie Thunderbolt Drives. Upon updating to Catalina, I've experienced constant system of failures all related to the thunderbolt drives. Apple needs to correct this immediately. This is not a problem with our drives, or cables, but with how the system interacts with the OS and Thunderbolt. This was a problem before with thunderbolt drives and the OS, and clearly they have not addressed it properly.

Yes, I have confirmed: it's been several days with the G-Drive mounted and being backed up to on the MacBook Pro running Mojave. No shutdowns.

And it’s been several days with the WD Firewire drive connected via Apple Firewire> Thunderbolt adapter to the iMac running Catalina with no shutdowns.  

So the problem clearly is that at least some Thunderbolt drives (in my case the G-Drive Pro Thunderbolt) are not compatible with Catalina. Took a lot of trouble shooting to narrow this down, but pretty convinced at this point.

Having a problem myself, consistent with this thread, that only started occurring after my recent "upgrade" to Catalina. My OWC Mercury Elite Pro Dual hardware raid box, using Thunderbolt 2, has been getting the spontaneous dismounts, typically during heavy disk operations. The most recent was just after booting a Windows 10 Parallels virtual machine that resides on the external volume and subsequently trying to start up a Windows app. I have been using this external drive for probably around 4-5 years, never had a problem. The OWC is not showing drive failures in its status lights. This last time, it was so bad when it disconnected, my Mac Pro (late 2013 trash can) froze up, then rebooted.

Let's be very clear, based on the consistent symptoms I'm seeing in this thread. Apple introduced a regression bug into Catalina, specifically with respect to external volumes, perhaps even specific to Thunderbolt ("2", in my case) i/o volume. I have no personal desire to phone apple support, as they are typically clueless to "real world" usage of their products, and I don't suspect there is a culture of q/a that endeavors to actively root out these issues that aren't part of their core delivered hardware functionality.

As an attempt to resolve, I reset PRAM, then ran diagnostics ("D" on startup), all hardware tested successfully, no errors. So I'm left to suspect that this is in fact a bug specific to Catalina, and I would also have to agree with another post suggesting that apple rushed Catalina out the door, as they frequently tend to do. I thought I'd be safe waiting until the 10.15.2 release, but sadly no, this release may have a critical thunderbolt i/o defect. I wonder if Thunderbolt 3 is affected as well.

Same problem for me, but my drives are various USB 3.0. Random ejects, sometimes folders hang whilst loading, then the eject occurs.

Also my old partitioned  Lacie, 2TB for Time Machine, 1TB drag and drop items, locks up randomly when coping files from either partition. The 1TB partition is currently dead now. Disc utility cannot fix the partition.

I suspect Catalina also.

same issues with my early 2015 MBP Retina upgraded to i7 3.1GHtz 16G RAM (after keyboard failure/replacement) and using G-Drive Mobile 4T external, but my symptoms are much weirder; my MBP has been running flawlessly for months, but now i experience not only the unprompted eject problems; they seem to coincide with memory usage, the wireless adapter appears to disconnect/reconnect also, and my cursor lags/jumps. this has all persisted through a complete wipe and fresh reinstallation of Catalina. i have no doubt that this is mostly an issue on the Apple side of things. why?

I am having the same issue. I'm running an iMac Late 2014. My external Thunderbolt drive was working fine using Catalina 10.15.1 and the issue started with upgrade to 10.15.3. My external drive is a WD Velociraptor 2TB Thunderbolt. My USB attached drives work fine. Tried running WD Drive diagnostics and Apple First Aid checks all passing with no issues. I have also tried resetting the SMC, moving data off the drives, re-formatting, and copy data back. I tried creating a test user to rule out issues with my user profile, no change, still have the problem. I purchased a Thunderbolt to USB-C/Thunderbolt-3 adapter to test the cable, drive enclosure, and drives. When connected to a Macbook Pro running Catalina 10.15.1 there are no issues or random drive ejects. This tells me that my cable and Velociraptor are working just fine. To rule out 10.15.3 I plan to try upgrading the Macbook Pro and if I can re-create the issue, if yes, then I will need to wait for an update and hope Apple fixes what is looking more and more like a bug in Catalina 10.15.3. I opened ticket with Apple, if for nothing else to officially log the issue.

Update: I was able to recreate the problem on a Macbook Pro after updating to Catalina 10.15.3 from 10.15.1. Additional observation is that as long as there is IO to the drive, i.e. reading from or writing to the drive, things remain connected. The drives never randomly eject so long as there is activity. I will now wait patiently for an update to hopefully fix the issue.

Mine got a failure when doing an import of around 300 images from USB flash media to Photos, where my library was on the OWC external raid set. Another time I was copying files from my MBP, connected to my LAN via wifi, to my Mac Pro on wired ethernet. Conversely, I have also had the raid volume abruptly disconnect while seemingly nothing was going on. I reinstalled Catalina from scratch, still had the disconnect problem. I've now upgraded my Mac Pro's SSD from 512gb to 2tb to avoid using the TB2 raid drive at all. Side bonus, was nice to go from 700MB/s ssd speed to 1300MB/s in the upgrade. But I've had the Mac Pro (late 3013 cylinder) since 2014, through multiple releases of the O/S, never had a single problem with the OWC Mercury raid tb2 connectivity until Catalina. The problems started within a couple of weeks of the upgrade to Catalina. I certainly could be experiencing a hardware failure of sort with the external drive, but there are no indicators of a drive problem on. the device, which is a dual drive raid mirror setup. I bought a new Apple TB2 cable, still disconnects. All signs seem to weigh more with a Catalina issue, but I can't say that is 100%.

Hi! I have the same problem with my Lacie 2big 6tb Thunderbolt 2 (aka my disk) too. Moreover, each time my disk was ejecting Finder was not responding and the only way to restart my imac 2012 was to hard reset. Otherwise I was seeing black screen of death (I have seen it many many times unfortunately). Following your suggestions I have bought a new thunderbolt cable (dod not help) and then I have installed Mojave on my second SSD and miracle! my disk appeared on desktop being successfully mounted. It worked!!! and I began thinking how to downgrade from Catalina to Mojave. But after hour or two the same problem appeared - disk ejected. So, in y case Mojave did not help. So, I just replaced thunderbolt cable with usb 3.0 and now it is just OK. The downgrade in speed (from 300 mb/s to 270 mb/s) is fine for me. Now I have two thunderbolt cables free ))) To be honest I was always under impression Thunderbolt is a killing feature from Apple, so I am absolutely discouraged how this problem can happen and not addressed by Apple men.