Comment by MBCook

I've also found that the fastest way to totally lock up a Mac kernel is to have some external hard drive fail while connected. You will be unable to open, quit, force quit, or reboot, and it won't boot up again unless that drive is disconnected.

Both MacOS and Windows start having issues if you have less than 10% of the disk free. The problem with the Mac is your ~/Library/Application support/ folder can get huge and take up a ton of space. Mine is currently at 55GB

When my Intel Mac ran out of disk space once, it became impossible to clear the space without rebooting (due to APFS's annoying journaling crap or whatever -- it would literally say "rm: can not remove [whatever]: no space left on device" or something), which caused Google Chrome to wipe all my local storage and cookies because it loves to do that when you run out of disk space, and there's no way to get that data back even if you do somehow clear space with the browser still running. I've been bitten by this many times on at least four different platforms. I wish it could just keep everything on disk instead of deleting it all? Like anything that deletes my data automatically can just go die in my opinion. This is one of the reasons I don't use Google Chrome anymore, another is how it deletes "old" history too (after 3 months) even if you have terabytes free, which is just so offensive I can't even explain it. Ungoogled Chromium lets you turn some of this stuff off, but when I moved to Mac I just started using Safari.

The only way to save my file system was to boot into recovery mode and run a verification with Disk Utility, then I was able to remove some files and get my space back.