Monterey struggling with External SSD

I am also having this issue on a brand new 14" Macbook Pro running Monterey. At first I thought it was an Apple Silicon compatibility issue, but from the others here it sounds like it is an issue specifically with MacOS 12.0.1. All of these external SSDs worked perfectly with zero issues on my 2015 Macbook Pro i7 running Catalina that I traded in. Now they randomly eject themselves and slow to a crawl, causing my whole system to freeze up. I was about ready to return my new Macbook until I found this thread that seems to confirm that it is a software issue and not hardware. I really hope this is fixed with a software update ASAP.

I have the same issue. I have a MacBook Pro and two Mac Minis. After upgrading the MacBook Pro and the Mac Mini I use to run our Zoom Room, I thought I was all set. Then I updated a second Mac Mini that I use as a media server. That one has two external SSDs: 1) Samsung 2TB EVO in an external enclosure, which mounts and works just fine and 2) a Micron 7.68TB SSD I use for video media.

The Samsung works fine. The Micron? Would not mount. So, I moved it to my brand new MacBook Pro (M1) and same result. Shows up in Drive Utility, but won't mount.

I tried erasing and formatting as a new APFS drive, which appeared to work. When I started copy a back-up media set back onto the drive, it disappeared and will no longer mount.

I love Apple... I really do, but every time a major OS upgrade happens, it creates problems with external media. Big Sur's main issue was with my Thunderbolt 3 Drobo. Took Apple a long time to fix that problem.

Oh, well... I guess I just won't use my 7.68TB SSD.

I have two Samsung T5 500GB external SSDs connected to a Mac mini (2018) via USB 3.1 (Gen 2).

I've experienced some of the same symptoms especially with regards to mount and unmounting external volumes. It seems that the Time Machine volume, in particular, takes a relatively long time to mount. This may be due to the fact that the Time Machine volume is encrypted. Once mounted the SSD seem to perform normally.

Regarding slow transfer rates, I noticed that some older USB keys (USB 2.0) are ridiculously slow and take a very long time to unmount.

- Pie Lover

Take a look at these:

OWC Express Portable Bus-Powered USB 3.0 Enclosure for 2.5" SATA Notebook HDDs & SSDs - Discreet Black

OWC Mercury Elite Pro mini USB-C 10Gb/s Portable Storage Enclosure

OWC Envoy Pro EX USB-C M.2 SSD Enclosure

However, I would contact OWC's Customer Support to find out which of their enclosures would best suit your particular Mac, SSD to put in it and budget.

OWC is the premier Mac 3rd party hardware provider.

I should add that there is definitely nothing wrong with the hardware. The same usb c drive works perfectly when accessed from a catalina install.

now I am downgrading to Big Sur, which worked fine. Will try a clean install on the internal drive…

i have similar issues with boot up times going from 20 seconds to over 5

minutes now. I have i5 Mac with 16GB memory, 2017. I suspect its because I’m using an External SSD to boot from. Monterey took ages to install as well. Maybe Apple are getting ready to ditch intel based macs and 3rd Party SSD Hardware.

I have had various issues with external SSD drives since upgrading to Monterey on a 2020 MacBook Pro. To summarize:

1. Carbon Copy Cloner backups to external Sandisk SSD via USB-C cable hang. Sometimes MacBook will just shutdown, sometimes it will shutdown and restart, and sometimes I will need to force it to shutdown
2. Disk Utility hangs when opening while the SSD is connected.
3. Inability to erase SSD from Disk Utility. Note I was able to erase it from a 2016 MacBook Pro also running Monterey and was able to run a full CCC backup from that machine
4. Random Finder hangs when SSD is connected
5. Inability to eject SSD even when it seems to be operating normally.
6. I also have a Samsung T7 SSD that experiences similar problems but not as often as the Sandisk.

I had none of these issues before upgrading to Monterey.

Had some time to spare , so I’d thought give another go.

I got rid of some unwanted software and cleaned up files with lost

links also this time I installed the Samsung T5 SSD software and to my surprise it thinks the drive is disconnected although the disk utility does see it and Monterey is operating on in all be it very slowly. I’m inclined to conclude this a Monterey issue. I thinks it’s back to Big Sur when I get time.

That's a good point since the firmware update, if any, should be backwards compatible with older versions of macOS. Just to be sure, you could verify the firmware version via System Report (for Big Sur and Monterey). Below is my configuration which clearly will be very different from yours.

- Pie Lover

I have similar issues with Monterey macOS 12.1 on late 2018 Mac Mini. I have two Samsung external SSDs (500GB on USB3 and 1TB on USB-C) connected , and a third external disk which is a LaCie 4TB (format Mac OS Extended Journaled). Experienced kernel panic a few times a day. Same problem in Safe Mode. Have also reset NVRAM or PRAM. Problem settles down after disconnecting external drives. Very frustrating.

I have been having this issue on my 2020 M1 Mini, still running Big Sur. Heavy data transfer can cause one of the drives connected via Thunderbolt/USB-C to disconnect. I don't see it happening on drives connected via USB 3

I have a two day old MBP M1 Max. 10/32/15 2TB. When I connect my Samsung 2TB T5 SSD, it sometimes takes a minute to mount. Accessing the files can take many minutes. The 3000+ NEF files can't be read in Lightroom Classic with any consistency. When I attempt to eject the drive, it'll will not eject and ask if I'd like to force-eject. When I force-eject the drive, it will not mount again unless I reboot the MBP M1 Max. My early 2013 MBP will easily read the drive with no issues.

Updated to 12.2.

I tried one more time with my 4TB Samsung EVO. I formatted it with Disk Utility to APFS. After that I unmounted it. Then when I tried to remount it, I got : "Impossible de monter « Test ». (erreur 49218 dans com.apple.DiskManagement.disenter.)"

So 12.2 did not solve the problem.

I have an intermittent eject/reading problem with an external Samsung SSD 860 EVO 2TB formatted as exFAT.

Within a few minutes of accessing the drive, it ejects and I have to use Windows to repair the drive to get my Air M1 to read it again, but then it's lather, rinse, repeat. Pretty much useless at this point.

Never had this problem before Monterey, so it definitely seems like a Monterey issue; it's as simple as that.

The problem is not only external SSD. I have regular LaCie HDs or 2TB and two of 5TB. I have problems with all of them. What problems?

1) Cannot erase

2) Cannot do First Aid

3) Cannot run TimeMachine on any of them

4) On the one drive where I have my live TimeMachine I can no longer run TM again. It snaps out of it.

etc.

I am at wits end. Apple support is useless, sent me to LaCie. LaCie yesterday succeeded to reformat one drive, and I could put TM on. Then today the same drive is again as sick as all others.

Apple, you either messed up Monterrey, or you worse, is it my fancy 16" MBP M1 Mac that has hiccups?

Btw....I confirm ultra slow loading of devices on DiskUtility. Weird.

Can anyone at Apple acknowledge that we are not all seeing ghosts, and that someone is fixing the problems I mentioned? As I see, I am far from alone, comforting me.

Thanks.