The system data issue on macOS is awful.

I use my MacBook for a mix of dev work and music production and between docker, music libraries, update caches and the like it’s not weird for me to have to go for a fresh install once every year or two.

Once that gets filled up, it’s pretty much impossible to understand where the giant block of memory is.

▲ prmph 5 hours ago | parent | next [-]

Yep, it is an awful situation. I'm increasingly becoming frustrated with how Apple keeps disrespecting users.

I downloaded several MacOS installers, not for the MacBook I use, but intending to use them to create a partitioned USB installer (they were for macOS versions that I could clearly not even use for my current MacBook). Then, after creating the USB, since I was short of space, I deleted the installers, including from the trash.

Weirdly, I did not reclaim any space; I wondered why. After scratching my head for a while, I asked an LLM, which directed me to check the system snapshots. I had previously disabled time machine backup and snapshots, and yet I saw these huge system snapshots containing the files I had deleted, and kicker was, there was no way to delete them!

Again I scratched my head for a while for a solution other than wiping the MacBook and re-installing MacOS, and then I had the idea to just restart. Lo and behold, the snapshots were gone after restarting. I was relieved, but also pretty pissed off at Apple.

▲

ryandrake 4 hours ago | parent | next [-]

It's just as bas on Windows. Operating Systems and Applications have been using the user's hard drive as a trash dumping ground for decades. Temporary files, logs, caches, caches of caches, settings files, metadata files (desktop.ini, .fseventsd, .Trashes, .Spotlight-V100, .DS_Store). Developers just dump their shit all over your disk as if it belongs to them. I really think apps should have to ask permission before they can write to files, outside of direct user-initiated command.

▲

intrasight 4 hours ago | parent | prev | next [-]

I can't help but think back to a conversation with my girlfriend in 1984. She had just bought a PC and I had bought a Mac.

She said "Oh, you bought a toy computer. How cute!"

I've owned every architecture of Mac since then, and I still think of it is my toy computer.

▲

jmalicki 4 hours ago | parent | prev [-]

Disk utility lets you delete them.

	▲	prmph 2 hours ago \| parent [-]
		Nope, I tried that, was blocked by SIP.

▲ vachina 6 hours ago | parent | prev | next [-]

Because Apple differentiates their products by their storage sizes, they also sell iCloud subscription. There is zero (in fact negative) incentive to respect your storage space.

▲

threetonesun 4 hours ago | parent [-]

Been a while since I needed to use it there but it always amazed me that the Windows implementation of iCloud was more flexible in terms of location and ability to decide what files got synced.

	▲	anonymars 4 hours ago \| parent [-]
		Ho ho, except for where it puts the photos. Those go into a subfolder of the system photos folder, and there's no configuration (yet you can configure the "shared photos" location) And then, should you try to set up OneDrive (despite Microsoft's shenanigans, it does simplify taking care of non-tech-savvy relatives), it will refuse to sync the photos folder because 'it contains another cloud storage' and you'll genuinely wonder how or why anyone uses computers anymore

▲ dotxlem 6 hours ago | parent | prev | next [-]

I had the same problem and had some luck cleaning things up by enabling "calculate all sizes" in Finder, which will show you the total directory size, and makes it a bit easier to look for where the big stuff is hiding. You'll also want to make sure to look through hidden directories like ~/Library; I found a bunch of Docker-related stuff in there which turned out to be where a lot of my disk space went.

You can enable "calculate all sizes" in Finder with Cmd+J. I think it only works in list view however.

▲ robin_reala 5 hours ago | parent | next [-]

I’d recommend GrandPerspective:[1] it’s really good at displaying this sort of thing, has been around for over two decades, and the developer has managed to keep it to <5MB which is perfect when you’re running very low on space.

[1] https://grandperspectiv.sourceforge.net/

	▲	braingravy 5 hours ago \| parent [-]
		I use GP, would recommend as well; it generates great color codes tree maps of your storage. Once you get used to navigating it that way, you won’t go back.

▲ dewey 5 hours ago | parent | prev | next [-]

Something like https://dev.yorhel.nl/ncdu with ("brew install ncdu") is great if you are okay with the command line. It's very annoying to drill down in the Finder especially if it's hidden directories.

	▲	mrbombastic 5 hours ago \| parent [-]
		in a similar vein if you are looking for a nice GUI, daisydisk is great: https://daisydiskapp.com one time $10 payment

▲ vintagedave 4 hours ago | parent | prev | next [-]

Also DaisyDisk! Beautiful app. Perfect for discovering this kind of thing.

▲ prmph 5 hours ago | parent | prev | next [-]

A ton of thanks. This "hack" allowed to finally see some stuff that was eating up a lot of my space and was showing up as "System Data". It turned out the Podman virtual machine on my MacBook had eaten up more 100GB!

▲ 1e1a 5 hours ago | parent | prev [-]

You can also just use du -hs, eg. to show the size of all subdirectories under ~/Library/Caches/ do:

  du -hs ~/Library/Caches/*

▲ zarzavat 5 hours ago | parent | prev | next [-]

The trick is to reboot into recovery partition, disable SIP, then run OmniDiskSweeper as root (as in `sudo /Applications/OmniDiskSweeper.app/Contents/MacOS/OmniDiskSweeper`). Then you can find all kinds of caches that are otherwise hidden by SIP.

	▲	prmph 2 hours ago \| parent [-]
		It shouldn't be this hard to clear unwanted data from my own computer

▲ piyh 5 hours ago | parent | prev | next [-]

Even worse on ipad. My wife is an artist and 100gigs of "system data" is completely inscrutable and there's zero ways to fix it besides a full wipe.

▲ John23832 6 hours ago | parent | prev | next [-]

Seconding.

I should not have to hack through /Libary files to regain data on a TB drive because Osx wanted to put 200gbs of crap there in an opaque manner and not give the user ANY direct way to regain their space.

▲ millerm 4 hours ago | parent | prev | next [-]

I simply run GrandPerspective (GUI app, https://grandperspectiv.sourceforge.net/), or dust (terminal app, https://github.com/bootandy/dust), to give me an idea of what is going on with disk usage.

	▲	rickmatt 3 hours ago \| parent [-]
		Thank you for this! I just downloaded it and identified over 50G of junk. It's just what I have been looking for to help manage my drive utilization.

▲ pdntspa 5 hours ago | parent | prev | next [-]

Equally egregious are applications that insist on using the primary disk to cache model data/sample data/whatever

▲

zbentley 5 hours ago | parent [-]

What should they do instead?

Like, assuming they need the data and it's inconveniently large to fit into RAM, where/how should they store and access it if not the primary disk?

	▲	mock-possum 4 hours ago \| parent [-]
		They should ask. Let users specify a scratch / cache location - preferably fast storage that’s not The OS drive

▲ drumttocs8 5 hours ago | parent | prev | next [-]

My 256gb Mac Mini currently has 65gb of "System Data" and 40gb of "MacOS"

▲ mbowcut2 5 hours ago | parent | prev | next [-]

Gotta hit that docker system prune -a

▲ mschuster91 5 hours ago | parent | prev [-]

> Once that gets filled up, it’s pretty much impossible to understand where the giant block of memory is.

Your friend is called ncdu and can be used as follows:

    sudo ncdu -x -e --exclude Volumes /System/Volumes/Data/

The exclude for Volumes is necessary because otherwise ncdu ends up in an infinite loop - "/Volumes/Macintosh\ HD/Volumes/" can be repeated ad nauseam and ncdu's -x flag doesn't catch that for whatever reason.