When emptying trash doesn't free space

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Level 2

254 points

When emptying trash doesn't free space

I recently copied a few large disk images (~140GB) from an external drive to my laptop, because I was going to reformat the drive.

After I no longer needed the images, I put them in the trash and emptied the trash.

The 140GB did not get freed up. Instead, Disk Utility lists about 140GB as purgeable. [1]

I looked around [2], but could not find a consistent definition of 'purgeable files'.

How can I get the OS to just free up the space from the deleted disk images?

I don't want to simply purge the purgeable files, because I haven't a clue what those files truly are.

Any tips would be appreciated.

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[1] I do not know how much space was listed as purgeable before this fiasco started.

[2] When I looked up purgeable files, Apple claims they only exist only if optimizing storage and using iDrive. I do neither. Further grubbing around found claims that files in Time Machine backups are purgeable (which is insanity because then all files would be purgeable). Other claims were that if the file system thought they were on an external drive, they would be purgeable. Finally, on stackexchange, the claim was made that it could be from files queued up for Time Machine backups that were never backed up.

All of this makes me think of people guessing at the number of m&m's in a jar.

MacBook Pro 15", 10.14

Posted on May 7, 2019 7:20 AM

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Answer 1

Best reply

Luis Sequeira1

Level 9

64,694 points

May 7, 2019 7:46 AM in response to Bill Rising

This space is likely taken up by Time Machine local snapshots.

You can list the existing snapshots in Terminal:

tmutil listlocalsnapshots /

You "thin" local snapshots to recover some disk space:

sudo tmutil thinlocalsnapshots / 140000000000 4

(the last one will ask for your password; type it blindly, and press enter; nothing will seem to occur when you type the password, that is normal)

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Answer 2

May 7, 2019 7:43 AM in response to Bill Rising

These are probably files in Time Machine's local snapshots, and probably backups of these same images.

Try this in Terminal:

tmutil listlocalsnapshots /

You can recover space from these local snapshots like this:

sudo tmutil thinlocalsnapshots / 140000000000 4

(the large number is close to 140G, and the final 4 is the highest "urgency")

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Answer 3

Bill Rising Author

Level 2

254 points

May 7, 2019 7:46 AM in response to leroydouglas

I did reboot my machine.

I have not yet reindexed spotlight, though, because I need my computer to give a training today, and the reindexing will likely last for hours. I'll try the reindexing tonight, and will post back.

Kinda scary to think that the files could be inadvertently trashed because of spotlight being a step behind.

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Answer 4

May 7, 2019 7:57 AM in response to Bill Rising

Bill Rising wrote:

I did reboot my machine.

I have not yet reindexed spotlight, though, because I need my computer to give a training today, and the reindexing will likely last for hours. I'll try the reindexing tonight, and will post back.

Kinda scary to think that the files could be inadvertently trashed because of spotlight being a step behind.

reindexing on my machine took about 5 minutes maybe I did not time it— "likely last for hours." and you got bigger problems.

Inadvertently deleting files? Did you mention this above? Seems a different issue all together, spotlight just an index.

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Answer 5

Bill Rising Author

Level 2

254 points

May 7, 2019 8:01 AM in response to leroydouglas

My 'will likely take hours' response is from how long Spotlight chugs away after putting in a fresh OS installation. So... perhaps it can go quickly, but I cannot risk it right now.

The reference to 'inadvertenly deleting files' comes from the way that Apple claims that purgeable files can be chucked at any time. If rebuilding the spotlight index is necessary for the OS to figure out whether something can be thrown away, this would be scary.

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Answer 6

Bill Rising Author

Level 2

254 points

May 9, 2019 5:15 PM in response to Bill Rising

It took a bit for most of the free space to appear after dumping the snapshots. There are still about 18GB purgeable, but this is nothing compared to 140GB.

I don't believe that rebuilding the spotlight index did much of anything. Still, I'll try this first the next time to see if the two are somehow related.

Thanks to all.

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