When attempting to attach an external SDD to a Mac mini (2018) running Big Sur (11.4), the operating crashes and restarts. Curiously, this doesn't happen every time.
The disk has an APFS container with several volumes including an encrypted Time Machine backup volume.
Has anyone had a similar experience and, if so, is there a workaround other than shutting down the computer before attaching the external drive?
- Pie Lover
Unfortunately, using diskutil alone to eject (even with sudo) did not work consistently. The screenshot below indicates that a volume is in use despite all of the container volumes being unmounted.
There may be interaction with Spotlight indexing that prevents the disk from being ejected. Fiddling with the privacy tab in the Spotlight Preference panel seemed to help in some cases.
Here is some advice from an Apple article on this topic:
If you can’t eject an external disk or storage device
> Log Out, then log in again. Try to eject the disk again. > Shut Down. Disconnect the disk from your computer, then start up your computer again.
- Pie Lover
Unfortunately, using diskutil alone to eject (even with sudo) did not work consistently. The screenshot below indicates that a volume is in use despite all of the container volumes being unmounted.
There may be interaction with Spotlight indexing that prevents the disk from being ejected. Fiddling with the privacy tab in the Spotlight Preference panel seemed to help in some cases.
Here is some advice from an Apple article on this topic:
If you can’t eject an external disk or storage device
> Log Out, then log in again. Try to eject the disk again. > Shut Down. Disconnect the disk from your computer, then start up your computer again.
- Pie Lover
Thanks. I believe that eject should automatically unmount any affected volumes.
As mentioned, I suspect Spotlight indexing especially with regards to the indexing of Time Machine backups. Ejecting the (top level) disk should work once (mds) indexing has completed.
I also noticed that I am able to eject immediately after recreating the Time Machine APFS volume on the external disk.
Ultimately, the best approach may be to shut down the machine prior to connecting or disconnecting an external (USB) drive.
- Pie Lover
Thanks for the response. I don't think that the problem is power related since the drive connects via the Mac mini's built-in USB-C port. Also, I had already disabled some of the energy saving features (see below).
- Pie Lover
Based on a few tests, ejecting the SSD device may help alleviate crashes stemming from physically disconnecting the drive. While I wasn't always successful ejecting with Disk Utility, I was able to use Terminal from an admin account (sudo diskutil eject /dev/diskname (replace diskname with the one listed as Physical Store by diskutil list external)).
- Pie Lover
Disk Utility Error Message
Get a 100W PD pass through adapter like this one SIIG's Dock.
Take the power and pass through the usb-c port of the adapter. Your external SSD may have insufficient power to be managed by the Mac.
Do not close the lid of the machine or let screen saver put the hard drive to sleep in your system preferences when using the external drive.
BlueberryLover wrote:
Thanks. I believe that eject should automatically unmount any affected volumes.
As mentioned, I suspect Spotlight indexing especially with regards to the indexing of Time Machine backups. Ejecting the (top level) disk should work once (mds) indexing has completed.
I also noticed that I am able to eject immediately after recreating the Time Machine APFS volume on the external disk.
Ultimately, the best approach may be to shut down the machine prior to connecting or disconnecting an external (USB) drive.
- Pie Lover
Something is not right here. I use that same Samsung T5 SSD with a 2019 16-inch Macbook Pro with no such issues. I use it for making and updating backup "clones" (mirrors the entire internal drive of the Macbook Pro) and I can simply eject from the Finder immediately after using it, without allowing mds or Spotlight to finish (the drive is not excluded from Spotlight, so it indexes it when it is allowed to, but ejects immediately when told to).
One question: are you using any of Samsung's proprietary software or drivers with these external drives? If so, they add additional complications to the interaction and could be causing the problem. It is best to use them as vanilla Apple-formatted drives without special third party drivers, software etc.
One of your screenshots shows multiple external T5 and it appears that you are using them to hold both Time Machine backups as well as external drive version of different MacOS, on the same physical drive? Do you have the problem when only one of the T5 is connected? Does the refusal to eject happen after specific activity, e.g. backups, something else?
You should consider downloading Etrecheck and posting the results here, people will look through what is installed and may be able to help you by finding something that conflicts.
Thanks Steve.
I had been using Samsung's T5 software (updated for Big Sur) but per your suggestion I've since removed it to see if the Samsung s/w is related to this issue.
Yes, you're correct. I have two T5 external drives each one hosting a Time Machine backup volume. Initially, I noticed problems ejecting each of the disks but more recently only saw the issue on the disk with the older versions of macOS. I haven't noticed any particular activity that correlates with this issue.
I took a quick look a EtreCheck to see if there were major issues. I didn't see any but noticed some minor issues stemming from the upgrades from Mojave to Catalina to Big Sur (e.g. obsolete Adobe updater tasks).
- Pie Lover
P.S. I was able to eject the disk exhibiting the issue after removing the Samsung s/w, Thanks for the tip.
After a few more tests, it seems that the Samsung Portable SSD Software for the T5 is the culprit. The SSD seems to work properly using Apple-only software. On the plus side, I can now eject my T5 SDD without problem.
Thanks again to Steve for the suggestion.
- Pie Lover
P.S. The Time Machine feature which permits multiple volumes to be used in a round robin fashion enables more robust backup strategies. In my case, I disconnect one of the backup drives after each backup to facilitate recovery in case of a ransomware attack.
I believe you need to use the umount command before you can eject a drive.
Big Sur Crashes when attaching external SSD to built-in USB port
