High Sierra wouldn't remove 320GB+ purgeable space. Please HELP!

[sdugoten]

I think this screenshot below pretty much explain the problem. The system report I have 424GB free space, but 325GB is purgeable. For whatever reason, Although the system report I have 424GB free space, the yellow bar "System" alone takes up 366GB space!!



The reason system was so big because I copy a 300GB file to the desktop yesterday. After I delete the file, I notice the TimeMachine complain there is not enough space to backup. And then all a sudden the backup needed space go from 220GB and jump up to 551GB as you can see in the screenshot. The Timemachine is actually backing up the 300GB file that I deleted yesterday.




Anyway got a clue how to fix this?

 

[h9826790]

That looks normal to me.

1) you copy 300GB file to the SSD

2) Your local time machine make an hourly backup for you when that 300GB files still there. However, due to APFS, it doesn't require extra space.

3) When you delete that 300GB files, you delete the original copy, but the local time machine actually need that original 300GB space to hold the backup data. So, Finder said the space can be free up (e.g. after that 300GB files copy to Time Machine)

So, your storage details shows system (which include the local time machine backup) still include that 300GB, but finder is not.

Time Machine is actually doing its job. If you want to recover that 300GB data now, you can do that, because the hourly backup data is there.

To "fix" it, you can remove that 300GB local time machine data (if you 100% sure you don't need those data anymore), or let your Mac connect to the TM hard drive, let it move that local TM backup data to the HDD.

To avoid it happen again, you can make a folder in your SSD. Exclude it in the TM backup option. And always copy and work with your temporary data inside that folder. Then your local TM will never backup those data, in other words, no need to keep occupy your SSD after you delete them.

 

[sdugoten]

I eventually use this command to find all the local timemachine snapshot

tmutil listlocalsnapshots /

And then delete them one by one using

tmutil deletelocalsnapshots <snapshot_date>


This "feature" with APFS + TimeMachine local snapshot is very annoying as time machine will cache whatever you dump into your computer locally on your machine. If you dump 300GB files on your desktop, it WILL cache it in the local snapshot. And it will stay on your computer even after you delete the original file. Yes, you just lost 300GB space even you have already delete the original file.

You will have to manually delete the local snapshot in TimeMachine to get back your space.

 

[h9826790]

I eventually use this command to find all the local timemachine snapshot

tmutil listlocalsnapshots /

And then delete them one by one using

tmutil deletelocalsnapshots <snapshot_date>


This "feature" with APFS + TimeMachine local snapshot is very annoying as time machine will cache whatever you dump into your computer locally on your machine. If you dump 300GB files on your desktop, it WILL cache it in the local snapshot. And it will stay on your computer even after you delete the original file. Yes, you just lost 300GB space even you have already delete the original file.

You will have to manually delete the local snapshot in TimeMachine to get back your space.

No, you didn't lost 300GB space. The system "utilise" that 300GB space. Hard drive is for storage something, keeping them empty is useless. And the TM doesn't expect a user keep everything locally without backup to the TM HDD for a prolong period of time. Also, you can free up the space by deleting the local TM snapshot if you really need them in hurry.

In fact, this kind of local snapshot make sense to me. It use the free space to minimise the chance that I may lost a file. However, I expect the system will automatically free up the space by cleaning up the oldest local snapshot (even if TM hasn't transfer it to TM HDD yet) if I really run out of space in the foreground.

In your case, Finder report you has 424GB space, I will expect you can really use 424GB if you want to. And It will automatically clear up the snapshot for you (when required).

If you don't like it, you should stop Time Machine (or manage the files in an excluded folder). The whole idea of Time Machine is to allow you to go back to any snapshot when required. In TM's point of view, that 300GB data was really there yesterday. And TM should use all free resource to maximise the chance for you to recover that 300GB data if you suddenly want to go back to that particular time stamp.

 

[Fishrrman]

I can't help but wonder...

What kind of "file" is 300gb in size ???

 

[BLUEDOG314]

You can turn the local snapshot feature off by doing "sudo tmutil disablelocal" in terminal.

 

[Weaselboy]

You can turn the local snapshot feature off by doing "sudo tmutil disablelocal" in terminal.

That no longer works in High Sierra.

 

[Fishrrman]

Weaselboy wrote:
"That no longer works in High Sierra."

Just wondering:
Is this the case IF the user has reformatted the drive to APFS?
or...
Is it no longer possible on drives that remain at HFS+, as well?

 

[Weaselboy]

Just wondering:
Is this the case IF the user has reformatted the drive to APFS?
or...
Is it no longer possible on drives that remain at HFS+, as well?

Good question. I don't have a running HFS+ HS install to test, but I think it is gone altogether. If you do "man tmutil" in Terminal to see all the arguments for that command, the disablelocal command is not listed any more.

 

[Pkupman57]

Im running HS on a HFS+ formatted SSD. The command to stop local snapshots no longer works for me either. I too would like to find a way to disable it. Or at least a way to move my local snapshots to my other internal HDD.