External USB SSD Disk Utility/First Aid Issue

Capt'n Butler

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Nov 4, 2023, 6:34:34 PM11/4/23

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Got an issue running Disk Utility/First Aid on a 512GB external SATA SSD
storing jpg and jpeg pictures. OS is Sonoma 14.1.

Disk Utility shows the SSD structure as:
Top level: JMicron Generic Media
Second level down: Container Disk
Third level down: My Extra Pix

First Aid runs and returns clean reports on the top and third levels.
But running First Aid on the second level Container Disk returns an
error message:

“The repair cannot be performed because one or more volumes are mounted.
: (-69566)
Operation failed.”

If I manually unmount the Container Disk using Unmount on the menu bar,
First Aid runs and returns a clean report.

Upon exiting Disk Utility, the drive is no longer visible in Finder
until unplugged/re-plugged at which point it is usable again

Running Disk Utility again after re-plugging, the same Mounted error
repeats. Repeated entire sequence several times. Same deal.

Problem? If yes- ideas to fix?

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Alan Browne

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Nov 4, 2023, 6:44:58 PM11/4/23

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First off, what prompted you to do the First Aid in the first place?

Far from expert on Mac OS disk anything, but given my past frustration
with DikUtility and "Repair" , etc. I'd

1) Assume the disk is okay and all the files are okay.
2) Get another disk and copy the files over to it.
3) Verify that it's okay ( don't ask - just look at the folder structure
and see if randomly picked files are where they should be ). Personally
I'd write a program to tree search and compare - because: masochist.

4) If that's okay: option: re-format the SSD and re-copy the files back
to it from the 2nd drive.

Move on with life.

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- John Maynard Keynes.

Jolly Roger

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Nov 4, 2023, 8:52:32 PM11/4/23

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That's expected behavior. The volume needs to be unmounted to be
examined properly is all.

If you aren't using Time Machine to back up the data on your Mac and
external drives, you should start doing so immediately so that you don't
have this constant worry whether your data will go bye-bye.

<https://www.macworld.com/article/229391/how-to-make-sure-time-machine-backs-up-external-drives.html>

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JR

Capt'n Butler

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Nov 5, 2023, 10:47:19 AM11/5/23

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It was just a routine periodic integrity check. I'll give your
suggestions a try. thanks...

Alan Browne

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Nov 5, 2023, 10:51:34 AM11/5/23

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On 2023-11-05 10:47, Capt'n Butler wrote:

>
> It was just a routine periodic integrity check. I'll give your
> suggestions a try. thanks...

See JR's explanation first.

Capt'n Butler

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Nov 5, 2023, 10:57:46 AM11/5/23

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On 11/4/23 8:52 PM, Jolly Roger wrote:
> On 2023-11-04, Capt'n Butler <rh...@tara.net> wrote:
>> Got an issue running Disk Utility/First Aid on a 512GB external SATA SSD
>> storing jpg and jpeg pictures. OS is Sonoma 14.1.
>>
>> Disk Utility shows the SSD structure as:
>> Top level: JMicron Generic Media
>> Second level down: Container Disk
>> Third level down: My Extra Pix
>>
>> First Aid runs and returns clean reports on the top and third levels.
>> But running First Aid on the second level Container Disk returns an
>> error message:
>>
>> “The repair cannot be performed because one or more volumes are
>> mounted.
>> : (-69566) Operation failed.”
>>
>> If I manually unmount the Container Disk using Unmount on the menu
>> bar, First Aid runs and returns a clean report.
>>
>> Upon exiting Disk Utility, the drive is no longer visible in Finder
>> until unplugged/re-plugged at which point it is usable again
>>
>> Running Disk Utility again after re-plugging, the same Mounted error
>> repeats. Repeated entire sequence several times. Same deal.
>>
>> Problem? If yes- ideas to fix?
>
> That's expected behavior. The volume needs to be unmounted to be
> examined properly is all.

Yeah, but what I'm not understanding is why DU/FA doesn't auto-unmount
this disk prior to running the scan as it does with every drive.

> If you aren't using Time Machine to back up the data on your Mac and
> external drives, you should start doing so immediately so that you don't
> have this constant worry whether your data will go bye-bye.
>
> <https://www.macworld.com/article/229391/how-to-make-sure-time-machine-backs-up-external-drives.html>
>

My routine TM backups include this external USB drive that's always
connected to my iMac.

Jolly Roger

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Nov 5, 2023, 5:16:40 PM11/5/23

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It probably tries, but some process is busy using it. For instance,
often Spotlight will be indexing a drive and it will fail to unmount as
a result.

Capt'n Butler

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Nov 5, 2023, 6:19:38 PM11/5/23

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That makes sense.

Capt'n Butler

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Nov 6, 2023, 10:32:36 AM11/6/23

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That was the likely culprit. It's running fine now!

--
There’s no problem so bad that you can’t make it worse.
- Astronaut Chris Hadfield

Jolly Roger

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Nov 6, 2023, 11:10:22 PM11/6/23

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Glad to hear it!

Ant

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Nov 7, 2023, 3:26:53 PM11/7/23

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Capt'n Butler <rh...@tara.net> wrote:

...

> > It probably tries, but some process is busy using it. For instance,
> > often Spotlight will be indexing a drive and it will fail to unmount as
> > a result.

> That was the likely culprit. It's running fine now!

How did you tell Spotlight to stop indexing so you could unmount?
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Capt'n Butler

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Nov 8, 2023, 10:27:56 PM11/8/23

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On 11/7/23 3:26 PM, Ant wrote:
> Capt'n Butler <rh...@tara.net> wrote:
> ...
>>> It probably tries, but some process is busy using it. For instance,
>>> often Spotlight will be indexing a drive and it will fail to unmount as
>>> a result.
>
>> That was the likely culprit. It's running fine now!
>
> How did you tell Spotlight to stop indexing so you could unmount?

I didn't-- I assume Spotlight completed indexing so First Aid could
unmount it as it was no longer being used.

Interestingly, after I made changes to-- or even just accessed-- the
Container Disk or its sub disk, I got the same FA error message.

Following a rest period-- I'm assuming after re-indexing was complete--
FA ran normally.

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