Help! Mojave 'System' is 700GB and growing. Can't empty Trash [Resolved Sort of]

[dix]

For some reason, according to the System Report, for my Mac my "System" is 710gb!

I noticed recently that deleting files from the Trash wasn't freeing up disk space, but put off troubleshooting because everything was working fine. However, as my Available Space has diminished I started experiencing problems, random freezes etc, and checked the Storage tab in About This Mac and saw that the System is using most of the 1TB drive's disk space.

Obviously 710gb is too big for Mojave, or any OS to be using. I deleted some Time Machine snapshots via the Terminal, but that didn't help much - and I still can't free up space by emptying the trash.

Tried booting into Safe Mode, did First Aid with Disk Utility and TechTools. The Carbon Copy Clone of my boot drive exhibits the exact same behavior. ...in fact if the clone is mounted, but not booted into, Get Info says it has 600gb available, but if I boot into that same drive it will only report 130gb available.

Any ideas here? Thank you in advance

[bayswater]

Weird. Have you tried any of the utilities that delete old cache files, etc? Or Grandperspective? It maps your drives. I've used it now and then when available space drops quickly to find a couple of large useless files. Is there a library that should be on an external drive that's in the Library folder for some reason? Stuff that should be on iCloud that isn't? A backup going to the wrong place?

[dix]

Weird. Have you tried any of the utilities that delete old cache files, etc? Or Grandperspective? It maps your drives. I've used it now and then when available space drops quickly to find a couple of large useless files. Is there a library that should be on an external drive that's in the Library folder for some reason? Stuff that should be on iCloud that isn't? A backup going to the wrong place?

Thanks for the prompt response!

Not a misplaced library or any other visible files I don't think. I scoured and deleted many gb of stuff before I noticed the bloated System (trashing them doesn't free up space anyway). Plus, whichever of the two boot drives is NOT mounted shows a drastically larger amount of free space.

I tried something called OmniSweeper. It identified an invisible folder called "usr" that's around 500gb, but I'm afraid to delete it. I'll try Grandperspective, but I still may need some guidance as to what's safe to delete.

Thanks again!

[mikehalloran]

I noticed the bloated System (trashing them doesn't free up space anyway)

SSDs cannot free up space immediately—not ever because they work differently. Garbage collection, built into the drive, should make the all the cells available to accept new data within 48 hours or so. TRIM, part of the MacOS, Windows and UNIX will clear all the cells within in 24–36 hours. It’s a continuous process so, if you erase a huge block of data, you can check the progress every couple of hours to see how much space becomes available. You’ll never notice this if you have enough free space but, if not, you’ll hit this wall.

TRIM must be enabled if you boot from a 2.5” SATA SSD — Apple blocks it because no Apple product has ever booted from one from the factory.

[dix]

Thanks Mike. I was hoping you’d chime in.

I did a big purge of visible files over a week ago and still have not reclaimed any disk space. In fact it looks like I’m losing some space spontaneously after each restart - none of this unprecedented according to what I find on the internet, but nowhere can I find a solution.

Again, if this 1tb disk is not being used as the boot drive it has plenty of free space, but if it is being used as the boot drive it only shows 120ish gb available. The exact same deal for the clone.

[dix]

....oh, and I didn't actually say it, but yes. I'm booting from SSDs, and TRIM is enabled. Btw, I also tried reindexing Spotlight, which was recommended by a few folks on Apple Discussions

[mikehalloran]

I did a big purge of visible files over a week ago and still have not reclaimed any disk space.

That's definitely not good. Even if an external SSD over USB where TRIM cannot be enabled, Garbage collection should work.

If not running an antivirus app, I'd download the free version of Avira and see if it can find anything. Run a full scan on all drives and see what shows up. It will want to install some browser extensions — don't for now (or not at all),

You can still ask Apple Support until Monterey is released but right now, I wouldn't even know what to ask. Failure to find anything in a complete scan can narrow things down a bit.

Next thing to look at is the Activity Monitor but do the above first.

[dix]

Downloaded Avira. It says I'm clean.

Emptying trash on all other disks works as expected, including the un-booted boot-clone. It's only the booted boot-drive that is losing available space. It almost seems like the trash is being emptied into the System somehow, since it grows bigger. Now at 711gb.

Get Info on the un-booted boot-clone says Available: "643.96 GB (466.04 GB purgeable)", whereas the booted boot-drive just says "Available: 128.63" GB. They swap this Get Info if I swap boot drives. I'm to sure what "purgeable" means here, but it's clearly related. ...sry, i hope my terminology is clear.

Let me know what I can try next. I can try Apple - soon I guess. Are you saying that Mojave support expires once Monterey is released?

Thanks so much as always, Mike!

[dix]

The (not really a) Solution:

Welp. After a day of tech support from my local Mac guru, and Apple's less than stellar phone support (the tech literally said, he's more of a Widows guy!) it became clear I should reinstall Mojave, which is what I've done.

So to any future time travelers having these issues that might come across this thread, my advice is to skip the googling and troubleshooting and cut to the OS reinstall.

Thanks again Mike and bays for your input.

[HCMarkus]

Welp. After a day of tech support from my local Mac guru, and Apple's less than stellar phone support (the tech literals said, he's more of a Widows guy!) it became clear I should reinstall Mojave, which is what I've done.

So to any future time travelers having these issues that might come across this thread, my advice is to skip the googling and troubleshooting and cut to the OS reinstall.

Thanks again Mike and bays for your input.

What the tech really meant, dix, is: I'm a Windows Guy. I love the view as I look out them. But I use macOS.

Right?

Glad you got it sorted.

[dix]

Welp. After a day of tech support from my local Mac guru, and Apple's less than stellar phone support (the tech literals said, he's more of a Widows guy!) it became clear I should reinstall Mojave, which is what I've done.

So to any future time travelers having these issues that might come across this thread, my advice is to skip the googling and troubleshooting and cut to the OS reinstall.

Thanks again Mike and bays for your input.

What the tech really meant, dix, is: I'm a Windows Guy. I love the view as I look out them. But I use macOS.

Right?

Glad you got it sorted.

Ha! That would have been better than what he did followed up with, which was "oh, I probably shouldn't have said that". He was also unfamiliar with Metal, and wasn't sure how Time Machine worked "back then" with Mojave. It really was a classic tech support call.

And incase you're wondering, reinstalling Mojave didn't fix my DP11 movie-lag issue....but at least life moves on now.

[funkyfreddy]

Interesting.... I'm having a similar issue. I moved all my Spitfire and Mac music files off of my main Macintosh drive on my MacBook Pro, backed them up on another drive but didn't get any disc space back when I moved the files to the trash and emptied it.

I must have deleted almost 200 gigs off my drive without getting any disc space back. I'm on Big Sur as of now.... and wondering if I should make the jump to Mojave.

I'm scared though.... Everything seems to have turned into a mega PITA since Catalina....

[mikehalloran]

See my earlier comments about Garbage Collection and TRIM. I went through this whole process of offloading (mainly all my NI VIs) and erasing a few weeks ago when my System drive was 98% full—took three days for any significant space to show up and now I have 1.1TB free.

This has nothing to do with any MacOS. Zip, zero, zed… and everything to do with the ways that SSDs work.

[funkyfreddy]

See my earlier comments about Garbage Collection and TRIM. I went through this whole process of offloading (mainly all my NI VIs) and erasing a few weeks ago when my System drive was 98% full—took three days for any significant space to show up and now I have 1.1TB free.

This has nothing to do with any MacOS. Zip, zero, zed… and everything to do with the ways that SSDs work.

Thanks Mike! That's good to know!

[mikehalloran]

More on how SSDs work: A few months ago, Apple support totally hosed my system by making suggestions instead of submitting my problem to Engineering as had been done in the past. I'll spare the details but it involved using Apple Configurator from my laptop to reset the T2 chip and initialize the internal RAID array on my iMac Pro.

Since my APFS Snapshots were now gone, the only recovery option after the T2 reset was a complete Time Machine restore of a 4TB System drive that was about 95% full. Normally, when using Apple Configurator initialize SSDs on any T2 or Apple Silicon Mac, those are "empty" replacement drives, not the case with my machine.

A full Time Machine Restore took a little over four days. My first thought was that Ethernet was the culprit but it wouldn't have made a difference. TRIM and Garbage Collection needed to make my internal SSDs ready for the new data and that's what took so damned much time. Had I upgraded my iMac Pro to the $2,700 8TB replacement set, it shouldn't have taken more than 12 hours or so.

Of course as I predicted, since that wasn't the problem, a full Restore didn't fix a thing. The culprit turned out to be that the older CodeMeter Runtime used by Autotune was incompatible with Monterey—finding and installing the current version fixed everything.