Sparsebundle Disk Image won't mount from external HDD

[i4k20c]

Hi all,

All of a sudden, my disk images within my external HD will not mount.

I have been using this method for years, by having a 5TB external Western Digital HD, and creating a 4.99TB sparsedisk image and then backing up files to it.

The disk image is a APFS volume with a password.

I had been using these external hdd's mid 2014 MBP running Mac OS 10.14.6 and while they always took a minute or two to mount, lately, they started taking a long time. I recently got a new 2021 14inch MBP running the latest OS and when i plugged one of the ext HD's in there using a USB-C adapter, it corrupted. The HD mounted, but when i went to click on the sparsedisk image and input password, it took a long time to mount, and than I had tried accessing my files. When I unmounted everything and plugged it back in, it again took a long time, but now half my files were deleted. And eventually all my files gone.

Now all of a sudden, when i try the other ext HD on my 2014 MBP, it is also taking a long time to mount (20 minutes). I tried plugging it once into my new MBP, but when it did not mount the disk image quickly, i quickly unmounted the HD and removed it thinking maybe the new mac is causing it to be corrupted and not wanting to lose my files.

Has anyone had this type of experience? Is there anything I could be doing that is causing the problem?

 

[chown33]

I'd start by checking the cables. The easiest way to do that is to swap the one you're using now with another cable.

Another thing to try is plugging into a different connector on the MBP.

 

[i4k20c]

I'd start by checking the cables. The easiest way to do that is to swap the one you're using now with another cable.

Another thing to try is plugging into a different connector on the MBP.

so i guess it would seem bizzare to me that two ext hd's with two separate cables would now experience that. i have tried both HDD's on two macs.

one problem im facing right now, is the ext HD is plugged into the MBP and it is saying i can't eject the disk image because it is use when it actually isn't. The last time this happened, i shut down my computer fully and unplugged the hdd once the computer was shut down which caused the files to be deleted.

i am not sure what the proper steps to do are when it states that the disk image cannot be ejected because it is in use even if nothing is using it currently.

 

[chown33]

If the only thing that worked was shutting down the computer, then I don't see many alternatives. Someone else may be able to suggest something

If you're near an Apple Store, maybe take it in, with at least 1 external HD, and have them check it over. It could be faulty hardware.

In any case, I don't recommend further trials using important data. If data has already been deleted, then you should experiment on something safer, such as fake data on a newly made sparse image, or a copy of your original data.

 

[i4k20c]

If the only thing that worked was shutting down the computer, then I don't see many alternatives. Someone else may be able to suggest something

If you're near an Apple Store, maybe take it in, with at least 1 external HD, and have them check it over. It could be faulty hardware.

In any case, I don't recommend further trials using important data. If data has already been deleted, then you should experiment on something safer, such as fake data on a newly made sparse image, or a copy of your original data.

can i ask you what the best method is for pw protecting a hard drive? to be honest, I just did it this way because 5-10 years ago someone on this forum suggested it and so i've kept doing it. most of it isn't really that confidential, but having it PW protected is just a protection against a bugler or something.

is there a better way to PW protect my HD? aka, am I really using the right approach for what i want.

 

[MacCheetah3]

You can skip the disk image aspect and format the drive(s) in encrypted APFS.

(When APFS (Encrypted) is selected, Disk Utility will prompt you to choose a password and optional password hint.)

one problem im facing right now, is the ext HD is plugged into the MBP and it is saying i can't eject the disk image because it is use when it actually isn't. The last time this happened, i shut down my computer fully and unplugged the hdd once the computer was shut down which caused the files to be deleted.

i am not sure what the proper steps to do are when it states that the disk image cannot be ejected because it is in use even if nothing is using it currently.

Did the Mac shut down properly (i.e. by itself after choosing Shut Down) or did you force shut down (i.e., hold the power button until it shut off)?

I have encountered “The disk wasn’t ejected because one or more programs may be using it” alert. For me, a Mac restart clears it up. By the way, that warning is typically correct. A system service or app might still be accessing a file on the drive even if there appears to be no activity/reason.

Now all of a sudden, when i try the other ext HD on my 2014 MBP, it is also taking a long time to mount (20 minutes). I tried plugging it once into my new MBP, but when it did not mount the disk image quickly, i quickly unmounted the HD and removed it thinking maybe the new mac is causing it to be corrupted and not wanting to lose my files.

Has anyone had this type of experience? Is there anything I could be doing that is causing the problem?

I switched to an encrypted Time Machine (which is encrypted APFS) backup a couple of months ago — a similar reason as you mention. From my limited experience, even an empty drive (1.5TB) needs about a minute to unlock. However, as the drive has been filling (now at ~1.1TB free), the unlock process seems to require more time though I don’t have verification. While I might expect to wait several minutes for a large volume to be decrypted, 20 minutes does seem excessive. But again, I have limited experience in this size (i.e., multi-TB) encrypted volumes.