My computer gave me the notice that I was out of disk space today. So I fire up DaisyDisk, run it as an administrator, and look at the report.
It is reporting something like 400 GB of system files. It is important to note that these are not photos, videos, or anything in my home folder. That is a separate thing.
No ability to explore them or anything, so I do not know what they are. I did a whole bunch of googling, and eventually rebooted the computer because somebody said that might help.
Just rebooting the computer freed up 350 GB. Now… I get that the computer might have caches or something. There are reasons for things to be on disk that are temporary. But when the computer is running me completely out of disk space and crashing software, that is not a well managed cache - that’s a problem. Especially since running SSDs close to capacity dramatically reduces useful lifespan.
It also should not be necessary to reboot to reclaim it. If I wanted a computer that crashed due to a poorly managed operating system and had to be rebooted all the time to work properly, I would be running Windows.
Anybody have an idea what this is that is eating all this disk space, and/or how to prevent the issue?
Cool. I torched that cache (although it wasn’t that big after the reboot), and I added a Keyboard Maestro cron macro that triggers every 15 minutes to hassle me if my disk ever has less than 30% available space. Just in case things act up again.
UPDATE - I torched that cache two days ago, and this morning my “every 15 minutes” KM script fired when I went to use my computer. Down from 360 GB to 260 GB, over the course of the past two days, without me adding much of anything.
Checked it in DaisyDisk. 58 GB of “still hidden” space, even after rescanning as administrator. Used Onyx to purge caches, to see if that solved things. Nothing. Rebooted, and all of a sudden I moved from 260 GB free to 360 GB free SOLELY from the reboot.
So something is still definitely going on.
And since a huge chunk is “still hidden” in DaisyDisk, it doesn’t seem like it’s something identifiable in the standard filesystem-specific ways.
I have not (yet?) experienced a problem on my M1 MacBook Air (16GB 1TB) with significant loss of internal disk space after updating to macOS Sequoia (I did not jump on the Sequoia train until v15.2).
May I assume that you have been searching the web and have seen the many reports of others having a similar problem? Proposed solutions seem to revolve around Spotlight, Time Machine, booting in Safe Mode, and various caches. MacOS Sequoia filling up with system data - Apple Community, for example.
I shut down my system most nights and boot clean in the morning. I don’t use Time Machine, but I have listed the external HDD that is always connected to my MBA in Spotlight’s Search Privacy window. (It runs a Carbon Copy Cloner backup every two hours.) I also add the external HDD that runs a daily backup, but that disk drive is attached only during a backup, which is also the only time that I can add it to the Spotlight Privacy window. It disappears from the Spotlight Privacy window when not connected.
Yup. I’ve rebuilt Spotlight multiple times, I’m not using Time Machine, I’ve flushed caches with Onyx and tried manually flushing a bunch of others I read about (some of which I didn’t even have), and “boot into Safe Mode” is basically “reboot your computer” with a minor twist. Rebooting seems to solve it when it happens, but my gripe is that it shouldn’t be happening at all.
There’s no reason for a computer that’s left running for two days to consume 100 GB of misc. disk space that’s completely untraceable, and there’s even less reason rebooting should free it all back up.