Tahoe endlessly consumes all free space, 270 GB, on M4 MacBook Pro

[sparky672]

I've had a M4 MacBook Pro since last April. Only have a couple hundred GB on my 500 GB drive. As of today, and for the last several months, I had something like ~270 GB available.

Then I "upgraded" to Tahoe and walked away. Come back a couple hours later to find the drive is full! I literally have 1.2 GB left (and shrinking) and the machine is now virtually unusable and I cannot open anything.

Ideas?? What is Tahoe doing that could literally fill up the drive? Aside from some visual things, I changed no system settings before/after the upgrade.

Thanks.

EDIT: I rebooted and it's now showing 78 GB available. In the storage section, looks like System Data is close to 300 GB!

EDIT 2: Been reading some Reddit threads about out of control Spotlight indexing. I've disabled and deleted the Spotlight index but something else is still causing the System Data to bloat out of control.

 

[ConradRoentgen]

This sounds like a nightmare. Please keep us in the loop.

 

[Starfia]

That reminds me a lot of upgrading to… Sequoia? And I think the runaway factor was local Time Machine snapshots. I seem to recall there's some command for purging them or something. (Presumably it would be advisable to attempt to find out whether that's what's happening before running commands.)

 

[thebart]

Not as drastic but I lost ~70GB after upgrade from Sonoma. I also have 512GB drive. I've rebooted, but nothing changed

 

[sparky672]

UPDATE:

This machine is fairly new with the stock operating system, with no modifications and no betas, so upgrading to Tahoe should have been painless.

There are quite a few Reddit threads detailing a Spotlight issue with Tahoe beta. Keep in mind, I have never installed MacOS 26 beta or any other beta OS on this machine. This was a fresh Tahoe install on release day.

I ended up recovering everything and I'm back up to ~275 GB free. However, I don't know exactly how, so no further details or steps will be posted.

• DISABLED Spotlight immediately. IMO, Spotlight is the root cause. I also tried deleting the Spotlight index. Many of the terminal commands in Reddit did not work for the release version of Tahoe, so I had to figure it out. However, none of these actions seemed to immediately recover any space or stop the free space from fluctuating before my eyes.
• Checked the Time Machine snapshots. Nothing of consequential size. Disabled Time Machine.
• Shut down and rebooted so many times, unsure if any of those mattered.
• Booted into Safe Mode a couple of times.
• Booted into Recovery Mode and ran Disk First Aid. Green checkmarks so I don't think anything was actually accomplished in this step.
• Installed DaisyDisk app. Gave it full permission to run as Admin. When I was merely scanning the drive, I noticed nearly all the free space coming back. Scanning does not delete anything so I cannot explain this observation.

Every time I'd reboot, I'd see free space randomly come and go. I'd see as much as ~100 GB free and then back down to ~25 GB free. When I ran the DaisyDisk scan, all of the free space, nearly 300 GB came back inexplicably.

After all free space magically reappeared, I used DaisyDisk to recover the hidden space, purgeable, snapshots, etc. and got the System Data down to a few MB with ~325 GB of free space. I left it alone overnight and it ended up ~275 GB free space which is about where I started. I turned Time Machine and Spotlight back on today and it seems to be ok so far.

 

[sparky672]

UPDATE:

Free space is slowly shrinking. Down to ~250 GB since my last post. Using DaisyDisk to inspect and compare, it's confined to System Data (not the user account) and it appears that VM swap files are simply multiplying.

/System/Volumes/VM/

There are twenty-three swap files in this folder, named "swapfile0", "swapfile1", etc., each one exactly 1,073,741,824 bytes (1.07 GB). The first one was created when I reactivated Spotlight about four hours ago. It looks like six new swapfiles are added every hour. Do the math on that... 144 GB per day... at this rate, I'll be out of space in less than 48 hours.

EDIT: Rebooting wipes out these VM files and all free space is released. But that solves nothing as to why this is happening in the first place. In Sequoia, I could leave my MacBook Pro running for weeks and never lose any free space.

Hours after last reboot and it seems to be holding at ~277 GB free.

 

[Fishrrman]

OP wrote:
"There are twenty-three swap files in this folder, named "swapfile0", "swapfile1", etc., each one exactly 1,073,741,824 bytes (1.07 GB)."

I disable Spotlight on all my Macs.
Never used it since it was first introduced some years' back.

I also DISABLE VM disk swapping on my Macs.
Works fine for me, NO crashes, no problems.
Of course, you have to have sufficient memory to do this, AND you must take care to manage your apps so that you don't end up with too many running at once.
But again, never a problem yet.

This policy worked well on my 2012 Intel Mini (10gb), on my 2018 Intel Mini (16gb) and on my recent m4 Mac Mini (32gb).

 

[!!!]

UPDATE:

Free space is slowly shrinking. Down to ~250 GB since my last post. Using DaisyDisk to inspect and compare, it's confined to System Data (not the user account) and it appears that VM swap files are simply multiplying.

/System/Volumes/VM/

There are twenty-three swap files in this folder, named "swapfile0", "swapfile1", etc., each one exactly 1,073,741,824 bytes (1.07 GB). The first one was created when I reactivated Spotlight about four hours ago. It looks like six new swapfiles are added every hour. Do the math on that... 144 GB per day... at this rate, I'll be out of space in less than 48 hours.

EDIT: Rebooting wipes out these VM files and all free space is released. But that solves nothing as to why this is happening in the first place. In Sequoia, I could leave my MacBook Pro running for weeks and never lose any free space.

Hours after last reboot and it seems to be holding at ~277 GB free.

If your swap is filling up then you need to check Activity Monitor (be sure to do View > Show All Processes) for what's consuming so much RAM.

 

[Nik]

Finally Apple is motivating us to get more than 512GB of storage! Amazing!

 

[sparky672]

Things have settled down. It's been holding at the expected ~278 GB free, and I've been leaving apps such as Mail, Messages, and Safari open all day just to be sure.

What happened and should I have simply waited for it to settle down after the Tahoe update?

I still cannot explain what happened, and I'm not so sure about it settling down on its own. Whatever the issue, all free space was consumed in its entirety and the machine was unusable - this certainly can't be expected/normal, especially after simply upgrading from the last release of Sequoia to the official release of Tahoe.

 

[gevalt]

Not as drastic but I lost ~70GB after upgrade from Sonoma. I also have 512GB drive. I've rebooted, but nothing changed

i commented on this in another thread. i have the same experience as you, losing about 70GB after upgrading to tahoe on my M2pro MBP. i deleted the local snapshots and that helped... until the next morning.

 

[thebart]

i commented on this in another thread. i have the same experience as you, losing about 70GB after upgrading to tahoe on my M2pro MBP. i deleted the local snapshots and that helped... until the next morning.

I don't have TM backup so I don't think that's it. Get info on macintosh HD says like 2GB purgable, negligible

 

[sparky672]

I don't have TM backup so I don't think that's it. Get info on macintosh HD says like 2GB purgable, negligible

I will agree. When this issue was first discovered, I inspected my TM snapshots and they were almost zero, nothing to explain the missing 278 GB.

 

[kagharaht]

I'm only missing 9GB of space after the update. So this issue seems to be randomly happening. iMac M3 here.

 

[MBAir2010]

I JUST LOVE THE FIRST SUGGESTIONS!
"hey my friend.....store your data on the cloud, aaah the nice fluffy bunny rabbit like cloud!

anyways this was my reaction image of what all M users are going through: