Disable local snapshots in High Sierra with APFS

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

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.

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?

My suggestion is you call Apple support ( 1-800-692-7753 ) and insist on speaking with a senior advisor because this is a bug in the High Sierra operating system which the senior advisor will report . Don't correct this on your own because this report will support an update to High Sierra and you can be one of the hero's to getting this much needed fix to the macOS .

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.

Argh...All this is ridiculous! I have to use ESET End Point Protection because of work and now EVERY TIME there is a 'local snapshot' it thinks that its a new drive, so every 10 minutes its asking me if I want to scan it....driving me crazy. WE NEED TO BE ABLE TO DISABLE THIS. I have my own Time Machine drive that I use, I don't want this ridiculous secondary snap shot. HELP APPLE!!

Thanks, but I'm not sure you're addressing my issue. It may be that my computer was always doing this silly local snap shot, but from what I can tell, this is new because I now have a list of local snapshots only beginning the day that I downloaded High Sierra. I also have my own backup drive for time machine already in place. There is no reason to have the local snapshots with my TM there...its an unnecessary redundancy. The real nuisance is that my antivirus software thinks that every time there is a local snapshot taken, that its a new drive, and so asks me if I want to scan this new drive. Always. This was never a problem before I upgraded to high sierra. this is a new thing and its annoying. There must have been some configurational change to affect this... but how do I stop it from happening. I'm not allowed to remove my Antivirus as its institutionally mandated. The only other thing I can think of is stopping the local snapshot. If I have time machine backing up every hour to my external drive then I don't need local snapshot doing the same thing. Unless it was already doing this, but it was invisible before and so my AV software wasn't detecting it.

Strange.

There is no reason to have the local snapshots with my TM there...its an unnecessary redundancy.

Local Snapshots are necessary for Time Machine to work.

I'm not allowed to remove my Antivirus as its institutionally mandated.

Either find another institution or have a Mac that isn't backed up, will never work properly, while increasing its exposure to malware and related threats. Your choice.

A third option is to fire the incompetent idiots mandating your antivirus software. That's my favorite because it saves institutions tons of money. I take only a small percentage.

C'mon Apple, this is just taking your loyal customer base for fools.

I've just had to turn down a short-notice paid remix job because I couldn't get space on my hard drive for reinstalling a couple of apps and their associated samples. After reading this I thinned the snapshots on my laptop SSD (256GB) and free space suddenly went from 15GB free to 130GB free. The snapshots had already been backed up, so I can't see why Time Machine needs to maintain them.

Yeahyeahyeah I know, buy a larger hard disk, but A) the space is there, just being hogged by these snapshots and B) Don't try to tell me the fix to something you created is to spend more money on your products - that's a justification that a heroin dealer would use, not befitting the manufacture of elegant technical products.

Where in the Developer Forum post you quoted is

sudo tmutil disablelocal

mentioned? The entire context is different -- it's how to allow local snapshots separately from the normal TM backup, not how to allow normal incremental TM to the specific user-defined backup volumes while at the same time disabling all local backup.
In fact, the Developer Forum thread you reference says (Sept./November '17) that "sudo tmutil disablelocal" causes TM to be disabled completely, see repsonses by "peter_voisin" and "M Tesla" .

If you have different sources for what you claim, please cite them,but otherwise, please be more careful.

This has nothing to do with the life of the drive (which happens to be a SSD in my case) or general performance. The OS is writing hundreds of GB of invisible data to the storage device without giving power users the choice of managing how or if this process works. For people editing large videos, this can make the difference between completing the project or not, as After Effects and similar programs need empty disc space for caching.

I don't understand how someone can reap tens of thousands of points by posting "that's the way it is" comments such as this. Not helpful at all. And, it is not solved, so there should not be a green check mark next to your name. If you have a close connection to Apple in some way, then you should relay this problem to their engineers.

Apologies - this was meant to be a reply to someone else in this thread, who said snapshots will automatically get deleted as necessary)

Hi, this is not my experience. I think there is a bug (I am updated to on 10.13.3). I have a 1TB drive. My free space got down to 48GB. I needed to install a 60GB audio application and knew my drive shouldn't be that full
Deleting Local Snapshots freed up over 150GB of space.

I use photoshop which uses the local disk for scratch space. When it doesn't have enough disk space, it runs very slowly. That's very compelling reason to not want local snapshots.

Totally agree with this!

We should be able to decide whether we want local backups or not. The lifespan of the SSD will be indirectly affected by this change.