Disable local snapshots in High Sierra with APFS

I want to disable this. I do not want any local snapshots in my ssd.

Turn off Time Machine's automatic backups. That's the only way to do it.

Local snapshots affects to the overall SSD lifespan.

There is no evidence of that, and Time Machine's local snapshots have little influence on the millions of write / erase cycles that occur just in a normal course of using a Mac.

Apple has many years of using solid state memory, in hundreds of millions of devices. There have yet to be any widespread reports of life-limited failures.

Do as you please though.

That's true in theory, but in High Sierra, all of a sudden I'm getting this: "Time Machine could not create a local snapshot to back up from because there was insufficient free space on the source volume(s)."

This seems to be a common problem under High Sierra and there is no way to turn off the local snapshots, which is the problem.

I'm trying to manually delete local snapshots with tmutil, and even though it says it deleted, the snapshot still is listed when I list the local snapshots. There appears to be a bug in the local snapshot management where High Sierra isn't deleting them un APFS.

I feel the same way about these snapshots "sudo tmutil thinLocalSnapshots / 10000000000 4" Go to terminal and copy and paste and login this will thin out a lot of these snapsots . I found that unchecking automatic updates and removing your disks slowed it down but didn't stop it ! If this continues and they don't fix this I am fuming about not being able to disable this . I want to keep my backups on an external drive where I have access to the fifes so I can delete them if I want , not in a hidden file I don't have permission to edit or even access it .I will get carbon copy cloner and disable time machine for good and wish I could delete it! "sudo tmutil disablelocal" was my go to command in terminal till they removed it.

Here's the solution (tip of the iceberg only):

This has nothing to do with local snapshots. Rather, TM had created an invisible monster file of a "backup in progress". Perhaps the backup process was interrupted for some connectivity reasons; perhaps the monster file would have disappeared when "progress" was resumed sometime in the future. (I have been away from my TimeCapsule ever since the monster file was created, so there has been no further attempt to back up properly and, perhaps, delete this (provisional?) monster file in the process.)

Deleting the monster file - indeed the entire "backup" folder contained in the (invisible) "Volumes" folder at the top of my HD - restored my free memory. The deletion can be performed very simply in the Finder via the trash; just make invisible files visible first by typing shift-cmd-period once the appropriate window is open. (Typing this again toggles visibility back off.)

And, yes, I did speak to Apple Support and hope this will get reported.

The snapshots are deleted as space is needed. There is no real advantage to disabling them or turning off Time Machine. See the last section of this article.

About Time Machine local snapshots - Apple Support

Thank you so much. This has worked for me: "sudo tmutil thinLocalSnapshots / 10000000000 4". Please see full thread: Re: Disable local snapshots in High Sierra with APFS.

Your command "thinned" a local snapshots that I was not aware the system had created. As a result, I have freed up nearly 40GB in SSD hard drive.

DaisyDisk still shows 8GB hidden space...so a bit more digging...

-T

Further to my last post it seems that " If you're using macOS High Sierra, another snapshot is saved before installing any macOS update.”https://support.apple.com/en-gb/HT204015

This is what has happened to me, I think.....when I installed the latest supplemental update https://support.apple.com/en-us/HT208397

There is a terminal command to turn off local snapshots: sudo tmutil disablelocal

It's from this Apple Developer's page: https://forums.developer.apple.com/thread/81171

If you don't have a Developer's account here's what it says:

Is there a way to turn on and off the local TM snapshots? On Sierra, there was "sudo tmutil enablelocal" but it's no longer supported.

Correct Answer by tclementdev on Jun 30, 2017 9:08 AM

1. Yes, this is similar to the current local snapshots implementation. I think it is represented in Disk Utility or About this Mac as "backup" or "purgeable" disk space. It's supposed to be automatically reclaimed as needed. And I think there was a trick where the Finder would display the free size of a disk as the actual free size + the purgeable size, so users wouldn't be confused as much.

But Snapshots (and clones) can be way more confusing, for example deleting files will not necessarily give you back disk space, if the files data is still referenced somewhere in clones or snapshots. So it's quite important to harvest snapshots periodically.

The 'tmutil listlocalsnapshots /' command will list all the snapshots but will not tell you how much size they occupy. By that, I mean the size that only they are referencing (.i.e. the size you would get back by deleting the snapshots). But that can be done, I just don't think Apple is showing that information anywhere for now. You're not supposed to have to worry about all this if Time Machine does its job correctly of managing the snapshots.

2. As far as I know, APFS snapshots are only exposed through the Time Machine local snapshots feature. That being said, you don't need to configure any backup disk or enable automatic backups to be able to create local snapshots (but they will be created for you as part of the automatic backups of Time Machine). I think local snapshots and regular backups will just be shown together when you browse the Time Machine history of your disk as is currently the case.

3. Just enable the "Back Up Automatically" checkbox from System Preferences > Time Machine. This will ask you to configure a backup disk. I don't think there is currently a way to have only local snapshots being created automatically, without also configuring a regular backup disk.

And to directly answer your question, in High Sierra you can no longer ONLY disable local snapshots. You can, however, turn of automatic backups. Then whenever you want to do a backup on your external Time Machine drive, make sure it's connected then click the Time Machine icon and select Backup Now. Simple.

In APFS the "local snapshots" aren't exactly snapshots -- they're file states. Because APFS doesn't write new copies of modified files, but instead appends blocks, the local "snapshot" is really just a pointer to a previous file state with a different block map.

In other words, these snapshots aren't occupying any additional space in APFS, so there's no "hidden file" to look for and delete!

That’s not (always) true.

TM local snapshots often occupies large SSD space, and you can’t do anything.

Try the following: if you have a 100 GB folder and you want to copy to your Mac which only has 90 GB free space (AND the local snapshot occupies cca 30 GB!) you can’t do that.

Simply try it if you don’t believe me!

If you run a Daisydisk, you can see the so called system files.

Try run these terminal command:

sudo tmutil listlocalsnapshots /

Here is the detailed steps to reclaim you SSD space - unfortunately this is only a temporal solution 😟

Solution: Reclaim storage back from "System" | MacRumors Forums

Best wishes,

Zsolt from Hungary

Under 10.13 (required for APFS), this should be included in the system's tracked 'Purgeable Space' now. My understanding of that command is that in APFS you're simply forcing a purge that might otherwise be unnecessary.

kaczurzsolt wrote:

That’s not (always) true.

TM local snapshots often occupies large SSD space, and you can’t do anything.

Try the following: if you have a 100 GB folder and you want to copy to your Mac which only has 90 GB free space (AND the local snapshot occupies cca 30 GB!) you can’t do that.

Simply try it if you don’t believe me!

If you run a Daisydisk, you can see the so called system files.

Try run these terminal command:

sudo tmutil listlocalsnapshots /

Here is the detailed steps to reclaim you SSD space - unfortunately this is only a temporal solution 😟

Solution: Reclaim storage back from "System" | MacRumors Forums

Best wishes,

Zsolt from Hungary

There was a bug among my snapshots

this is the only thing that fixed it

I lost nearly half of my 512GB of disc space to local snapshots overnight, or so it seems. It started with Time Machine reporting that it was backing up "281GB of 271GB", where 271GB was indeed the total of disc space I was then using. Next morning, the system alerted me that I was running out of disc space, and making recommendations as to what to delete. (As explained elsewhere, the folder sizes shown in the Finder still add up to something like 270GB. But System Info under "About this Mac" reports "system" use of 238GB, where the actual use as reported by the Finder is closer to 10GB.) I'm now down to, ostensibly, 12 GB of free memory - 3 days after turning off automatic backups, and beginning to panic slightly.

Any suggestions of what to do?