Looks like some combination of defragging & balancing has done the trick! The space that was previously marked UNREACHABLE is now UNUSED, and my disk space is back to normal:

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       227G  105G  103G  51% /

Thanks for the wiki link, Btrfs is new to me and I’ve definitely got some learning to do

Just one drive, it was a clean Linux install with no funky stuff going on. I’ll have to look into Btrfs cleanup more, last time I did it the disk just filled up even more

Legend! It found a second filesystem named “UNREACHABLE”:

It looks like an exact duplicate of my main filesystem “/@rootfs”, I’m guessing this is why my disk space filled up. Do you know how I’d go about removing the duplicate? (If it’s safe to do so)

Interesting, this could be it? I haven’t configured any mounts on this device yet, but when I tried one of the other suggestions from this thread and use btdu, I get this error:

$ ./btdu -x /
Fatal error: The mount point you specified, "/", is not the top-level btrfs subvolume ("subvolid=5,subvol=/").
It is the btrfs subvolume "subvolid=256,subvol=/@rootfs".
Please specify the path to a mountpoint mounted with subvol=/ or subvolid=5.
E.g.: mkdir /mnt/sda1 && mount -o subvol=/ /dev/sda1 /mnt/sda1 && ./btdu /mnt/sda1

Note that the top-level btrfs subvolume ("subvolid=5,subvol=/") is not the same as the root of the filesystem ("/").

I’m fairly new to the workings of Btrfs so this is jibberish to me right now, but I’ll look into it more

EDIT: Nevermind! I was just using the tool wrong. I needed to mount my btrfs “sub-volume” then do the scan against that:

sudo mkdir -p /mnt/btdu

sudo mount -o subvolid=5 /dev/sda1 /mnt/btdu

sudo ./btdu /mnt/btdu

ncdu

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

There is one listed: ID 256 gen 137604 top level 5 path @rootfs Looks like it is just my filesystem though?

For music prod on Linux, have you tried Reaper?

Good solution, cheers! I also followed the other commenter’s idea to add it as a KDE shortcut so I can use it on demand.

I guess I’ll just need to be careful not to paste a bazillion lines of text lol

Works awesome! Thanks for introducing me to xdotool, what a helpful utility. Question: what does the --file flag in your command do? I can’t find it in the manpage

It depends entirely on the company you work for. Even then, I wouldn’t exactly describe the work as “chill”