I was reading TidBITS talk earlier today on my Mac Studio and a warning popped up, mail has to quit since there is no more space on the hard drive. Hilarious! I have 2TB, I use maybe 500GB. No way! Wait why do I only have 1GB free???
I had 1.5TB of system data, whaaaaat where did it come from oh no.
After about 1-2 hours of stress and reading and poking, it was because I had to use Chrome to download some data (Reddit data from Arctic Shift), and it sends a little data, sends a little data… so Chrome makes a new little ~15kb file every 5 seconds or so in its cache folder. There were maybe 25,000 little files (if you do the math it doesn’t add up though).
I managed to get it all back under control to try again (threw the files in the trash, emptied, that didn’t work mild panic, restart cleared it all out). I found a terminal command to start Chrome with a cache limit, which I set to 1GB (which is actually too large).
So, the process is working, but the cache files are only about 8,300 files for about 410MB at the moment, however, my drive space is down to 1.14TB when it should be around 1.5TB, and the System Data is 500GB – so, clearly it’s not just the Chrome cache in the Chrome cache folder (Library/Caches/Google/Chrome/Default/Cache), some other thing is growing massively along with it. (Keeping track of all the little files?) The data file is going on to an external drive.
What is going on, and how do I control it so it doesn’t take up all the space on my hard drive? (I still have to get the comments part of the Reddit data, I could start Chrome with like 10MB of cache space….) (I would rather not use Chrome but Arctic Shift uses some download thing I think that isn’t in Safari or Firefox, and clearly whatever it is is causing some problems in some way.)
If you’re using anything that snapshots the drive, such as Time Machine or a backup program, you won’t recover your space until the snapshot is deleted.
If that isn’t it, then you need to figure out where the space is being used. I use OmniDiskSweeper but there are alternatives. GrandPerspective and DaisyDisk are popular.
(I wonder if either does a better job of completely scanning a drive? OmniDiskSweeper is being blocked by permissions, and running with sudo doesn’t help.)
I do have Time Machine, but it is set up to only run when I run it manually. (I think that makes a difference here?) I suspect it shouldn’t grab cache files, and the data download was going to an external drive (not included in TM).
I LOVE Omni! #NeXT
I tried using the Opera browser (if I understand it, the download site requires Window API: showOpenFilePicker), and the same problem occurred. Ran it overnight, this morning had used up 1TB of disk space. (I’m wondering if I just try smaller data grabs and restart my Mac each time, or maybe use my old laptop to try it and see what happens.)
Hi Nat - wondering if you’ve made any progress in slimming down your “System Data”, a problem I’m sharing with my Mac Studio nominally with a 1TB drive. Currently, Storage figures tell me I’ve 993.48GB of 994.66GB used - and my System Data is taking up 584.96GB. Having set it to store messages in the iCloud - which shows that it’s holding 265.64GB - it surely shouldn’t be holding this also on my hard drive, should it? Am bewildered!
Storing messages, emails, contacts, etc. in iCloud doesn’t mean it isn’t also completely local on every user account that is syncing to iCloud. It just means it is also synched via iCloud.
Look at it this way:
Disconnect from Internet
Open Messages
Notice that you can still view every message
because they’re all on your Mac.
To reduce size of the Messages store, you need to turn on message purging.
Whatever it was, it was specific to the Arctic Shift web-based data downloading – that was causing whatever it was (tons of little files? one massive file? lots of medium files?) and filling up the hard drive. I wasn’t able to figure out the specifics, but it was bonkers. Currently I am using the Arctic Shift API via a Python script and that has no problems, so it was something about how the web front end for Arctic Shift and its downloading works (it downloads a little bit, a little bit, a little bit, over and over, but the space the process took up was magnitudes larger than the actual data files which were less than 1 GB). Whatever it was really shouldn’t have happened, though, but I’m not sure what the root cause was.
Even if you do manual TM backups, the internally saved snapshots will continue until all space is filled. However, these will delete themselves when more space is needed, so they shouldn’t have caused your message that there is no more space on the hard drive.
Many thanks, Michael… what you say makes entirely good sense. I’ve not seen a means by which to switch on “message purging” though - where should I look? I’m a little cautions, though, having a long history of communicating by email and not wanting to lose a record of some discussions. There’s no doubt I have a lot of junk within my mail but I don’t want to risk deleting something of importance that’s hidden within it. Even with a bigger hard drive, though, the time would come when I’d overfill it once again… Anyway, hoping and grateful for any steers…
Thanks for that, Nat… sorting this sort of issue is hard work, isn’t it? I’ve been using Macs since soon after the launch of the 128kb in 1984, getting mine just a few months later - and am finding this is the most frustrating issue ever. When I have time to dig around my “system data” files, I find odd files - many of minimal size but some of tens of MBs and remain bewildered about whether it’s safe to delete them or how best to copy them in such a way that they can - if ever I need - be recovered. Oh well… thanks again!
