Local Snapshots of Time-Machine

The plot thickens...

I checked my "Storage" in "About This Mac" and it showed 385 GB for System. I also had a long list of local snapshots. But I was curious and ran Omni Disk Sweeper.

I had the Storage display open and as Omni Disk Sweeper was running, I watched the "System" space jump down to 35 GB, which is much more accurate. Here is the final result:

The System space has already started to creep back up. The "Documents" area in the chart was originally "System". This agrees with "df -h" that I did originally too:

Filesystem Size Used Avail Capacity iused ifree %iused Mounted on

/dev/disk1s1 932Gi 472Gi 455Gi 51% 4345007 9223372036850430800 0% /

devfs 188Ki 188Ki 0Bi 100% 650 0 100% /dev

/dev/disk1s4 932Gi 3.0Gi 455Gi 1% 3 9223372036854775804 0% /private/var/vm

map -hosts 0Bi 0Bi 0Bi 100% 0 0 100% /net

map auto_home 0Bi 0Bi 0Bi 100% 0 0 100% /home

All this makes sense because I have a ton of Xcode developer files and lots of VMs in my home directory. I did not delete any Time Machine local snapshots.

So, I'm going to have to conclude that my initial hunch was correct. This was just standard flaky Spotlight behaviour. Don't delete those Time Machine backups. Spotlight is kind of like a quantum indexing system. Avoid taking any action based on something scary you might see. Just the act of observing will change the behaviour and may trigger the system to eventually correct the data.

Before removing these "snapshots", my disk was full up to the brim... These snapshots were occupying 50% of my disk, and they are beginning to come back, slowly but alas, surely.

Incidentally, I've disabled Spotlight since quite a while, now (and removed the Spotlight index...) (for the same reasons...)

Regards.

PS: 'OTHER' contains my VirtualBox images, for whom could be wondering... 😁

Hi,

Assuming you have somewhere, on another disk or on iCloud a Time Machine backup of your workspace state.

To remove (TOTALLY) the local "snapshots"

Copy/paste the commands below in your terminal.

For the ones in the System:

sudo tmutil listlocalsnapshotdates / |grep 20|while read f; do tmutil deletelocalsnapshots $f; done

(type enter)

(enter your admin password)

For the ones in your Home folder:

tmutil listlocalsnapshotdates / |grep 20|while read f; do tmutil deletelocalsnapshots $f; done

(type enter)

(no need password)

Yesss these things exist at both locations....

(wait a bit, this will take some time...) (when you see the cursor back, it's done)

You can notice immediately the effect on your disk space, but it's better to restart just afterward. Like this, the file system will create a new "snapshot" corresponding to your workspace state. You can now work safely in your workspace while APFS creates regularly new snapshots of your workspace state.

You may have to do this procedure every time you have deleted very big files.

Regards.

Hello Paz.americano,

That's not from snapshots. Space used by snapshots would not be visible. Snapshots are outside of the filesystem.

You can run Omni Disk Sweeper (https://www.omnigroup.com/more/) to find out where all your space is going. Just don't use it to delete anything. That is your system folder. Even if you could delete part of it, it would be a very bad idea if you were successful.

However, it would be very interesting to see what is taking 2.8 TB of space in /System.

quote: "it would be very interesting to see what is taking 2.8 TB of space in /System."

Let me guess.... Virtual memory? 😁 😁 😁

NB: I always test on my own machine these kind of tricks, and more than once, before even daring to post them.

Incidentally, one find really these snapshots at both places. Don't ask me why.

Oh Yessss. I know (I'm photographer and cineast). And it seems to me the best place (I try to avoid the hits of shovel 😁) to repeat once again that (almost) none of the people who post here in this forum is Apple (corporate) programmer. We (try) to program on it, but we aren't responsible of all that mess.

That’s interesting. Thanks for the follow-up. I never use the “Storage” displays because they are often so wildly inaccurate. But I guess they now have some value with APFS snapshots. This display seems to be able to report the space used by snapshots. I’ll have to look at this more closely.

Very interesting indeed. I get similar results: almost HALF of my disk is now free while it was full up to the brim before...

On the panel Time Machine preferences, it is said "The oldest backups are deleted when your disk is full" 😕 (eeeeek) I'd have greatly preferred that they are deleted when the free space on my disk is half-full (or less), otherwise I can't see very well how I can work like this...

PS: Out of subject (albeit...) when a memory-hog process eats all the RAM (and all the — possibly yet left free by TM — disk space by virtual memory overuse, etc., etc.), there are good chances that this impacts ALSO the shared RAM for video memory, no? What could explain all these display glitches reported here and there...

I only want my workspace to be roomy and stable, is it really too much to ask?

I don't need 'auto-save' I'm big enough to make myself backups of my files, on another disk than my system disk, and regularly...

And, incidentally:

I don't need either highly memory-consuming "background" tasks to "find faces and objects" in my 98576+ photos (the dude who has invented that should be summarily executed).

And I don't even need yet another memory hog to find (how, when, where is the report of its findings?) malwares on my Mac. Sophos used to work perfectly for me since years until it begins to slow down by verifying each and every of these #&@$ "snapshots" on my disk.

See what I mean?

Post Scriptum: Any hunch about the impact of these memory hogs on the shared video memory?

Almojgar wrote:

See what I mean?

No. I don't.

Spotlight is a fundamental technology underlying modern version of macOS. You can try to disable it if you want. I'm not sure that it entirely possible. If it is, then you should consider your machine seriously compromised. Any problem you encounter would be unique to your machine. No solution you find would be considered applicable to anyone else. You're on your own.

Snapshots reside outside of the file system. I don't know if anyone has come up with a way to easily and accurately identify just how much space they consume (or rather, the deleted and old file versions that they index). Apple maintains very tight controls on which apps have access to low-level snapshot APIs. Only legitimate 3rd party backup apps are allowed access. I don't think Sophos would qualify in that backup category.

At first I thought that this "System" field might be a way to easily identify how much space snapshots consume, since Apple obviously has full access to its own APIs. But I was able to reproduce this problem, or at least something that looked identical to it. Snapshots were not related. It was just normal Spotlight flakiness. While I don't suggest that anyone trust these kinds of Spotlight total reports, I also don't recommend disabling Spotlight.

But EVERY problem here is supposed to be UNIQUE for any machine. Because any user is, him/her too, unique.

It's not (only) a technological problem, it's a philosophical problem.

We are supposed to obediently follow the 'expected behavior' of a theoretical user to whom nobody, actually, ever, never asked his/her opinion.

Sorry but the size of that sheepyard is too small for me. More precisely, Apple' ill pigs wallow too much in my vital space.

It's not to that OS itself to decide when, how often, and where it puts my backups until the f$#&g disk be full up to the brim (by the by, actually these files are ALSO in your system, run the command with sudo after having deleted all snapshots in your home with no sudo, and you'll quickly understand what I meant...)

It's not to Spotlight to decide when and why it interacts with the Internet while I'm only searching for files on MY disk. Besides, this fundamental technology underlying modern version of macOS is totally unable to find files in any Library, therefore it is OBVIOUS that TrashMe do NOT use it.

It's not to some cracked programmer in Cupertino to decide that me, The User, must inevitably and permanently search in each and every of my photos for f@#$ing "faces and objects" at the price of a total blockage of all my other tasks, etc., etc.

Correct? or not?

Because if it's not, it's the precise difference between Democracy and a rogue dictature.

The total of space freed, here, was of about 90GB...

One snapshot per hour is it really reasonable...