Mac mini has about 75G of disk usage I can't account for

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Mac mini has about 75G of disk usage I can't account for

I have a Mac mini that our family uses as a shared server for media. It has an external drive with a very large music library. Recently, I wanted to upgrade Mac OS and was told that there was not enough disk space. I have been looking, but I cannot determine where this disk space is being used. Here is what I see in the Storage tab from "About this Mac":

So it seems like there's a lot in "Other".

There are only four user accounts on this machine, so I used "du" to find how much is in each User's folder:

That's less than 5G, so my problem is not in there.

Then I looked at all the top level directories. This is what I see:

I think that's normal -- the Volumes are mostly external, and I assume the "System" folder contains them somehow?

When I look at the Disk Utility it seems to show that there are Volumes on the hard drive that I cannot see. Here's the "Macintosh HD" -- other volumes approximately 85G:

Now I look inside, and I see:

Still other volumes. Now I look in the data:

So the 82G are in the data, which is what I would expect, but where?

Also, am I right that the 22 G is dedicated to the OS?

Any help that one could offer would be very welcome!

Mac mini, macOS 11.5

Posted on Feb 13, 2022 11:18 AM

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Answer 1

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rpg25 Author

Level 1

62 points

Feb 15, 2022 4:29 PM in response to rpg25

Found the solution with the help from Apple Support. There was an old copy of a Pictures library (50Gb!) that had been synced from iCloud onto the drive. I'm not sure why the `du` program wasn't able to see that: even though this was in ~/Pictures, du on ~ didn't add up the memory used there nor, somehow was it attributed to either me as a user, or to Pictures in the Storage analysis.

The Apple person got me to look at Manage in storage, and "Reduce Clutter" and it showed up there.

Whew!

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Answer 2

Feb 14, 2022 5:16 AM in response to rpg25

As @den.thed suggested, starting in safe mode can clear out most disk caches and other "stale" system storage.

One other thing. Do you have Time Machine enabled? While I did't see any Time Machine volumes listed, if you connect and manually do backups, if the drive is not connected, Time Machine will be doing local backups. you can do that in terminal by

tmutil listlocalsnapshots /

Don't for get the slash as it designates the root directory. If so, you can remove them using

tmutil deletelocalsnapshots {mount_point | date}

Also, you wouldn't happen to be using Carbon Copy Cloner or other cloning up to back up your system? The latest versions can typically be using the snapshot feature of APFS and creating snapshots on you drive, which would be added to other. If so, you would need to use those apps to manage the snapshots and remove them and in the future disable that feature to maintain disk space.

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Answer 3

den.thed

Level 10

91,540 points

Feb 13, 2022 7:20 PM in response to rpg25

Other was an issue for many of us in Catalina and Big Sur. I have a 500 GB SSD in my 2018 Mac Mini and 50 or 60 GB of Other, didn't didn't matter so much. Seems like it was a bug, because after I upgraded to Monterey, the Other category is no longer a problem.

Try this,

1) Eject and disconnect those external drives.

2) Start up in Safe Mode and check the used disk space.

see > How to use safe mode on your Mac - Apple Support

3) Then see if the Mac Mini will allow you to upgrade to macOS Monterey.

4) Then after you have successfully upgraded, reconnect your external hard drives.

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Answer 4

Feb 13, 2022 2:04 PM in response to rpg25

The graphical displays are a bit confusing.

You may want to open Terminal and do:

diskutil list

It will break out the volumes and drives a little better as independent entities. It may make things a bit clearer as to which volumes and disks are using up the data.

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Answer 5

den.thed

Level 10

91,540 points

Feb 14, 2022 6:47 AM in response to woodmeister50

Yea' I never could figure Other out.

TM, CCC, iOS backups, system files, etc...

Plus Other was very inconsistent from one macOS version to the next....

10.14 had a little, 10.15 had more, 11 had a lot, 12 is now called System Data with less

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Answer 6

rpg25 Author

Level 1

62 points

Feb 13, 2022 6:08 PM in response to woodmeister50

Alas, this did not solve my problem. diskutil list only shows the partitions, and doesn't give any more information than the graphical disk utility:

rpg@goldmanmilymini Volumes % sudo diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI ⁨EFI⁩                     314.6 MB   disk0s1
   2:                 Apple_APFS ⁨Container disk1⁩         121.0 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +121.0 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume ⁨Macintosh HD⁩            22.3 GB    disk1s1
   2:              APFS Snapshot ⁨com.apple.os.update-...⁩ 22.3 GB    disk1s1s1
   3:                APFS Volume ⁨Macintosh HD - Data⁩     82.3 GB    disk1s2
   4:                APFS Volume ⁨Preboot⁩                 291.7 MB   disk1s3
   5:                APFS Volume ⁨Recovery⁩                623.4 MB   disk1s4
   6:                APFS Volume ⁨VM⁩                      2.1 GB     disk1s5

The problem remains that I can't account for approximately 50 Gig of the 82.3.

When I look at the system info about storage again, I see this:

That "Other" is the problem. The little brown sliver is the user data, and this display gives me no clue about where the "Other" is hidden, or what it is.

Really baffling. I could probably rebuild the system, and reinstall the operating system, but ... that seems like an awfully Windowsy thing to do.

Somehow I have the disk space equivalent of dark matter!

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