Edit: Solved!
Unfortunately I’m not sure exactly what fixed it, because I was running btrfs commands like a madman.
Some combination of the following caused my 100GB labelled as UNREACHABLE to turn into UNUSED, which allowed that space to be written to as normal:
sudo btrfs balance start -v /
sudo btrfs filesystem defrag -v /
sudo btrfs filesystem defrag -v -r /
Also the tool btdu was incredibly helpful!
One of my linux boxes ran out of disk space, which surprised me, because it definitely didn’t have that much stuff on it. When I check with df it says I have used 212GB on my / path:
$ df -h /
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 227G 212G 5.2G 98% /
So, I tried to use du to see if maybe a runaway log file was the cause, but this says I have only used 101GB on my / path (this is also more in-line with how much space I expected to be used):
$ du -h | sort -h
...
101G /
Using those commands with sudo outputs the same sizes.
My filesystem is Btrfs, I’ve tried the suggestion to use btrfs balance start ... but this actually INCREASED my disk usage to 99% lol
So my question is… what on earth is using the remaining 111GB?? Why can I not see it in du?
I typically investigate with
ncduwhich gives very useful visualization like :--- /home/fabien/Prototypes/esphome/.esphome ---------------------------------------------------------------------------------------------------------------- /.. 3.1 GiB [######################] /platformio 218.1 MiB [# ] /build 28.0 KiB [ ] /idedata 8.0 KiB [ ] /storageand let’s you iterate. Here for example you’d go into
platformioand get another view, pressdto delete files or directories that aren’t needed anymore if it’s a stale project e.g.node_modules. Go back, etc.So yes, warmly recommended, both on desktop and remote servers. It’s way easier IMHO that
du -sh ./directorythencd, rinse and repeat. It’s also way WAY faster then GUI equivalents … because you navigate and take action, e.g. delete, with your keyboard.All that being said, if it’s about your filesystem rather than your files, it probably won’t help much. I don’t know enough about btrfs to help unfortunately.
Oh this one is very cool! Unfortunately it also only shows the same 101GB being used:
ncdu 1.22 ~ Use the arrow keys to navigate, press ? for help --- / ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 93.1 GiB [###########################] /home 6.5 GiB [# ] /usr 790.4 MiB [ ] /var 173.0 MiB [ ] /boot 12.8 MiB [ ] /etc 1.7 MiB [ ] /root 1.3 MiB [ ] /run 44.0 KiB [ ] /tmp @ 4.0 KiB [ ] initrd.img.old @ 4.0 KiB [ ] initrd.img @ 4.0 KiB [ ] vmlinuz.old @ 4.0 KiB [ ] vmlinuz @ 4.0 KiB [ ] lib64 @ 4.0 KiB [ ] sbin @ 4.0 KiB [ ] lib @ 4.0 KiB [ ] bin . 0.0 B [ ] /proc 0.0 B [ ] /sys 0.0 B [ ] /dev 0.0 B [ ] /media e 0.0 B [ ] /srv e 0.0 B [ ] /opt e 0.0 B [ ] /mnt