Macintosh HD nearly full - numbers don't add up - hidden 500 GB

[Eneco]

Hey there,

I just checked the available storage on my main drive and was surprised about how little space I have left. So I investigated where this was coming from. This is what Disk Utility says:

Capacity: 2 TB
Used: 1,69 TB
Free: 310,67 GB

In Finder my Macintosh HD drive contains 4 main folders:

Applications: 9,36 GB
Library: 15,68 GB
System: 10,11 GB
User: 1,15 TB
-------------------------
Total: 1,18 TB

But the numbers don't add up. So where are the missing 510 GB? I used a tool to show me the hidden files and folders on my drive. But there is no trace of files worth 510 GB:

So where are these 510 GB? What's going on here?

 

[maflynn]

Download and run OmniDiskSweeper (its free) It will provide a sorted list of your files/folders and show you where all your space is going. It includes system and hidden folders

 

[Eneco]

Thanks for your fast reply. Unfortunately OmniDiskSweeper also XX. It also says there is only 311 GB of free storage left, but the numbers of the individual files and folders don't add up to that number:

 

[Fishrrman]

Download DiskWave from here:

DiskWave Homepage

It's small in size and free.

Open DiskWave and go to the preferences.
Put a checkmark in "show invisible files".
Close preferences.

The DiskWave window shows you all your drives in plain English (no ridiculous graphical formats).
Click on any drive.
Now, you'll see what's ON the drive, listed in order of "largest to smallest".
You can easily locate what's eating up your space.

 

[Eneco]

Download DiskWave from here:

DiskWave Homepage

It's small in size and free.

Open DiskWave and go to the preferences.
Put a checkmark in "show invisible files".
Close preferences.

The DiskWave window shows you all your drives in plain English (no ridiculous graphical formats).
Click on any drive.
Now, you'll see what's ON the drive, listed in order of "largest to smallest".
You can easily locate what's eating up your space.

Unfortunately the numbers also don't add up, like with all the other tools. All file sizes combined are about 1,18 TB, but the used disk space of the overall drive is calculated with 1,61 TB.

What's going on here?

 

[edubfromktown]

Disk block size may be a factor.

Do you have a large number of very small files? They will occupy more space than their actual file size...

 

[Taz Mangus]

My suggestion would be to do a full system backup, erase the drive, reinstall macOS and migrate data from the backup.

 

[KALLT]

What does  → About This Mac → Storage say?

Have you moved, copied or deleted large amounts of data or used a cleaning tool recently? Some of that data might still be held by an APFS snapshot. It may also be that the statistics shown in Disk Utility are not up-to-date.

I am surprised that you have no purgeable storage.

 

[Fishrrman]

OP:

Important questions:
Do you use time machine?
Could some of this space be taken up by "local snapshots" or "local backups" (or whatever they're called, I don't use tm)?

 

[Eneco]

Disk block size may be a factor.

Do you have a large number of very small files? They will occupy more space than their actual file size...

Yes, there are a lot of samples from different software instruments. But the required space for each instrument (according to their system requirements) adds up to the actual number of 1,13 TB not 1,61.

What does  → About This Mac → Storage say?

Have you moved, copied or deleted large amounts of data or used a cleaning tool recently? Some of that data might still be held by an APFS snapshot. It may also be that the statistics shown in Disk Utility are not up-to-date.

I am surprised that you have no purgeable storage.

The same as all the other tools:

Yes, I downloaded and installed a lot of new samples from instruments lately and therefore deleted a lot of zip and rar archives in which the instruments were packed in.

OP:

Important questions:
Do you use time machine?
Could some of this space be taken up by "local snapshots" or "local backups" (or whatever they're called, I don't use tm)?

Yes, I use Time Machine, but excluded the sample folder which is 1,13 TB large. So the actual data being backuped is very small.

 

[Taz Mangus]

Yes, I use Time Machine, but excluded the sample folder which is 1,13 TB large. So the actual data being backuped is very small.

There could be a lot of space take up by time machine local snap shots.

Try running from terminal: tmutil listlocalsnapshotdates

This will show you how many local snap shots are locally stored on your internal drive.

 

[Eneco]

There could be a lot of space take up by time machine local snap shots.

Try running from terminal: tmutil listlocalsnapshotdates

This will show you how many local snap shots are locally stored on your internal drive.

This is the result:
2020-05-30-223919
2020-05-31-212444

 

[Taz Mangus]

I am not sure that 2 time machine local snapshots would account for 500GB. If you wanted to recapture the storage used by the local snapshots:

tmutil deletelocalsnapshots 2020-05-30-223919
tmutil deletelocalsnapshots 2020-05-31-212444

Not sure which version of MacOS you are using but if you want to disable the Time Machine local snapshots use timutil disablelocal. Catalina does not support disablelocal.

 

[Eneco]

Removing these snapshots didn't free up the 500 GB of space. Guess I will just backup everything and do a reinstall then ...