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mikegem

macrumors newbie
Apr 25, 2012
26
34
There can be various issues that cause the external drive to keep unmounting/disconnecting on mac:
  • The drive didn't connected properly
  • The data cable is damaged
  • USB cable connector got damage
  • Hardware or software issue
  • A USB port is damaged
Furthermore, there is a risk of data corruption as well while transferring data between the external drive and Mac. However, to fix the issue, you can try the below fixes:
  • Check if your mac is recognizing the drive
  • Resolve an issue using disk utility
  • Change finder settings in your mac
  • Recover or backup your drive
  • Change the drive’s format
Hope this will help!
None of these helps. It's a problem inherent to Monterey, through 12.5.1.
 
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mikegem

macrumors newbie
Apr 25, 2012
26
34
I am currently experiencing this issue as well, I have been going through this forum for a few days now mulling over the possibility that this was happening to my Macbook Pro (15Inch-2017). My computer is currently having a battery service issue so I thought the external hardrives unmounting randomly was caused by this. It is not. Monterey is definitely the issue here. I think there is a bug with how Monterey deals with powered/unpowered USB Hubs. Once I plugged in my hardrive directly (no hub) to my computer, (after unlocking it due to the weird unmount via [sudo pkill -f fsck] through terminal) it worked like a charm. No random unmounting at all.

I'm probably going to revert back to Big Sur. External HDD support through USB Powered Hubs should be a no brainer. Not sure why this hasen't been fixed in Monterey yet.
I have this problem on a 2018-style Mac Mini (Intel) and a MacBook Air M2, both running Monterey. Never had the problem on the Mini up through Catalina, but then I 'upgraded' to Monterey. The MB Air arrived with Monterey installed.

I've tried everything mentioned by prior posters and more, no change. This keeps me from using the Mini as my network backup host, which worked well until Monterey.

I just don't get Apple lately. So many reliability regressions.
 
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danlmac

macrumors newbie
Sep 4, 2022
1
0
Los Angeles, California
Following this thread with great interest. I'm not a tech guy; I'm just a long time Mac user. I'm not certain this problem is confined to Monterey.

I've got a 2018-ish MacBook Air, which is still running Mojave. Last month, one of my external hard drives wouldn't mount on it; it showed up (greyed out) in Disk Utility, but I couldn't run Disk First Aid on it. Tried everything - new cable, restarting, different ports, even a different (and older) MacBook. Two days later, nothing could make it mount. Thought I'd have to go to a data recovery place, but figured I'd try Disk Drill first, which had been recommended to me. (It's not supposed to fix a damaged drive; it's supposed to help recover data.) With the free version, I could see that all the files were still there, so I bought the full version, and started the recovery. Out of the blue, the drive appeared again, mounted on the Air. Drive has been fine ever since.

Cut to last week. I bought a new Mac Mini (M1) which, of course, runs Monterey 12.5.1.
Same thing happens with a brand new external drive from Seagate. Wouldn't mount on the new Mini, or the Air running Mojave.
Ran it through Disk Drill, and it mounted after several minutes.

No idea if using Disk Drill actually did the trick, or if it was just a coincidence.

Gotta say, this problem makes me really skittish.
 

leexy

macrumors newbie
Oct 6, 2015
4
2
I found that the following (temporary) solution works to mount the unmounted disks. I noticed that after First Aid is complete, the disk will be put in read only mode; a restart solves this.

Open Terminal
sudo pkill -f fsck

Anyways, if your disk happens to be ExFAT, and you remember improperly removing the disk the last time you used it, chances are, fsck is holding it hostage (metaphorically, of course). fsck is trying to repair the disk, but it will stall forever, so you want to launch Disk Utility, and the Terminal. Try to mount the disk, and switch to Terminal and write sudo pkill -f fsck. The disk will mount in read-only mode, and from there, you can repair it with First Aid in Disk Utility. This won't work for non-ExFat drives, as macOS manages them differently.
 

JordanMacRumors

macrumors newbie
Oct 24, 2022
4
0
I've been following this thread for a few weeks as I've had the same disconnecting drives issue. I just upgraded to Ventura and am still having the same problem. Has the update fixed it for anyone else?

My drives won't disconnect if I use either of the following hubs:
https://www.amazon.ca/Wavlink-Docking-Station-Charging-Ethernet/dp/B09X1GQFW2/ref=sr_1_6?keywords=wavlink+13+in+1&qid=1666642874&qu=eyJxc2MiOiIxLjM0IiwicXNhIjoiMC44MSIsInFzcCI6IjAuOTIifQ==&sr=8-6


They do disconnect if I use either of these:

 
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BrianBaughn

macrumors G3
Feb 13, 2011
9,637
2,409
Baltimore, Maryland
Been running my Mac Studio M1 Max for a few weeks now. I have six 3.5" HDs in three or four different kinds of housings (three on all the time) and three SATA SSDs connected via USB adapter cables. There's one powered hub and one unpowered. I will wean myself off this confusion in time.

I haven't had a dismount yet.

I keep the spinners going with Amphetamine as it's pretty bad when they spin down. I don't allow the Mac to sleep although my two monitors do.
 

TinRobot

macrumors newbie
Nov 26, 2020
5
2
I'm having this problem on my Mac Studio running Monterey. Does anyone know if it has resolved with Ventura? I never had this problem with my older iMac. Same drives, except I got a new SSD external and it also ejects. Basically, all my various drives get ejected at one time or another so it is not the drive or a cable or it would be isolated to one of the drives.
 

macskiman

macrumors newbie
Jul 14, 2008
7
5
I haven't had it happen yet, but I figure it's too soon to say, and I take extra precautions. It most commonly has been happening for me with my Time Machine Drive. So, for fear of having a corrupted backup, I monitor a backup closely. First, I go into settings and make sure the hard drive is not going to go to sleep on my 2020 Intel MacBook Air running Ventura. Then I keep using the computer while the backup to the external WD drive is happening. I don't leave it connected and make sure to do the next backup before so much has changed that the backup will take a long time.

I have had it happen also when transferring large files to external drives.

This information might not be very helpful, but since no one else has responded and it is still early days for Ventura, I thought I'd give some feedback FWIW.

I have several external USB drives and would like to leave them connected all the time, as I often did with my MacBook Pro, which I never updated to Catalina (the last macOS it could handle).
 

photo_maker

macrumors newbie
Nov 6, 2022
2
0
This is happening to me on multiple WD and Seagate drives. It worked just fine before the update. I don't know what to do and I have a lot of work that I need to access but it keeps randomly ejecting the HDs.
 

photo_maker

macrumors newbie
Nov 6, 2022
2
0
I'm having this problem on my Mac Studio running Monterey. Does anyone know if it has resolved with Ventura? I never had this problem with my older iMac. Same drives, except I got a new SSD external and it also ejects. Basically, all my various drives get ejected at one time or another so it is not the drive or a cable or it would be isolated to one of the drives.
It still happened to me on Ventura just now after updating
 

Algr

macrumors 6502
Jul 27, 2022
315
346
Earth (mostly)
When I was having this problem, I suspected it was a bad hub, but when I got a new mac the problem went away. I also discovered that "Put hard disks to sleep when possible" results in a big performance hit.
 

jdb8167

macrumors 601
Nov 17, 2008
4,729
4,420
I have a repurposed 512GB SSD from a 2013 Mac Pro in an OWC case designed to work with Apple's incompatible sort of M.2 devices. It worked fine with the upgraded Mac Pro but was consistently unmounting under Monterey. With Ventura it seems to be fixed. I copied about 50 GB of data and left the drive mounted all weekend and it worked without any issues.

Edit: This is on an M2 MacBook Air.
 

scottcampbell

macrumors 6502
Aug 7, 2017
343
812
Following.
I hoped the problem was with my old computer I was replacing, but now it’s occurring on my brand new MBP. I was going to start trying different cables and whatnot, but it sounds like it’s a software issue.
 

scottcampbell

macrumors 6502
Aug 7, 2017
343
812
For what it's worth, my problem appears to be solved.
Ventura 13.0 and I unchecked > Settings > Battery > Options > Put hard disks to sleep when possible
 

Biffs

macrumors newbie
Jul 23, 2015
28
12
Cullercoats, NE30, UK
"For what it's worth, my problem appears to be solved.
Ventura 13.0 and I unchecked > Settings > Battery > Options > Put hard disks to sleep when possible"

Thanks - now trying this through energy saver on my M1 in Ventura.
 
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antiprotest

macrumors 68040
Apr 19, 2010
3,993
13,967
@WinterWolf90 I updated today actually on this thread:


They're working fine again now on Big Sur. It was a painful downgrade as I had to factory reset then update from Catalina to Big Sur. It took ages and I had to install all my apps again. However I rely on external drives for work, so I had no choice. I'll remain on Big Sur now.
I am not even the one who has to go through this and I feel like crying.
 
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antiprotest

macrumors 68040
Apr 19, 2010
3,993
13,967
For what it's worth, my problem appears to be solved.
Ventura 13.0 and I unchecked > Settings > Battery > Options > Put hard disks to sleep when possible
If it is a timeout problem Amphetamine should fix it. The app, not the drug.

But from reading this thread I am not sure that's it though. Maybe report back after a while.
 
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EFXAD

macrumors newbie
Dec 15, 2022
3
2
I'm running an M1_Ultra max memory etc. My old Mac Pro trash can running Monterey started dismounting the drives. It's no better on M1 box even with ventura. I did what everyone else did; new cables new drives etc. had ZERO effect on the prob. The drives do show back up after a reboot for a random amount of time. Apple has really gone downhill on their coding... even the IOS 16 stuff is having issues on my phone & iPads. But on the plus side home kit seems to be working better now.
 
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scottcampbell

macrumors 6502
Aug 7, 2017
343
812
"For what it's worth, my problem appears to be solved.
Ventura 13.0 and I unchecked > Settings > Battery > Options > Put hard disks to sleep when possible"

Thanks - now trying this through energy saver on my M1 in Ventura.
Did it fix your problem, like it did mine?
 

pastrychef

macrumors 601
Sep 15, 2006
4,753
1,450
New York City, NY
I'm running an M1_Ultra max memory etc. My old Mac Pro trash can running Monterey started dismounting the drives. It's no better on M1 box even with ventura. I did what everyone else did; new cables new drives etc. had ZERO effect on the prob. The drives do show back up after a reboot for a random amount of time. Apple has really gone downhill on their coding... even the IOS 16 stuff is having issues on my phone & iPads. But on the plus side home kit seems to be working better now.

Same for me. I've had USB drives dismounting since my Power Mac G3 days and it still happens to me today on my Mac Studio.
 

schneideris

macrumors newbie
Nov 3, 2009
2
0
I'm running an M1_Ultra max memory etc. My old Mac Pro trash can running Monterey started dismounting the drives. It's no better on M1 box even with ventura. I did what everyone else did; new cables new drives etc. had ZERO effect on the prob. The drives do show back up after a reboot for a random amount of time. Apple has really gone downhill on their coding... even the IOS 16 stuff is having issues on my phone & iPads. But on the plus side home kit seems to be working better now.
I am running MacBook Pro with M1 Max and the same issues. Cannot say that HomeKit is any better based on my experience.

I was really getting frustrated with it and looking all sorts of Google results up. In the process I may have found something given that the one USB stick (was happening with another one too and both being tried through multiple converts to USB-C and hubs with constant disconnect issues) that I was having the most issues with now appears to be settled down. WhatI did that appears to have solved the problem (fingers crossed) was:

System Setting -> Displays -> Advanced and then turned off "Prevent automatic sleeping on power adapter when the display is off". Even though I was at the keyboard and therefore the display had no reason to sleep, this may have something to do with it. I can only say that because it is the only thing I have changed in my setup.

1672531496870.png


UPDATE: Left the computer to complete the transfer and it appears that when the screen went to sleep it caused a problem with the copy. I have unplugged the external monitor (that is connected via USB-C cable) and will try again.

UPDATE 2: Back to failures. Unplugging the monitor did nothing, though I did not reboot afterwards. Ug!
 
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