I noticed that I only had 5 GiB of free space left today. After quickly deleting some cached files, I tried to figure out what was causing this, but a lot was missing. Every tool gives a different amount of remaining storage space. System Monitor says I’m using 892.2 GiB/2.8 TiB (I don’t even have 2.8 TiB of storage though???). Filelight shows 32.4 GiB in total when scanning root, but 594.9 GiB when scanning my home folder.
Meanwhile, ncdu (another tool to view disk usage) shows 2.1 TiB with an apparent size of 130 TiB of disk space!
1.3 TiB [#############################################] /.snapshots
578.8 GiB [#################### ] /home
204.0 GiB [####### ] /var
42.5 GiB [# ] /usr
14.1 GiB [ ] /nix
1.3 GiB [ ] /opt
. 434.6 MiB [ ] /tmp
350.4 MiB [ ] /boot
80.8 MiB [ ] /root
23.3 MiB [ ] /etc
. 5.5 MiB [ ] /run
88.0 KiB [ ] /dev
@ 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 [ ] /srv
0.0 B [ ] /mnt
I assume the /.snapshots folder isn’t really that big, and it’s just counting it wrong. However, I’m wondering whether this could cause issues with other programs thinking they don’t have enough storage space. Steam also seems to follow the inflated amount and refuses to install any games.
I haven’t encountered this issue before, I still had about 100 GiB of free space last time I booted my system. Does anyone know what could cause this issue and how to resolve it?
Isn’t that RAID 0 and generally a bad idea? Since one disk failure can bring down the whole system.
Probably. I never looked into how it actually works with BTRFS.
You can set the metadata and data independently as RAID0, RAID1 or other levels depending on the number of disks and your desired level of data loss risk.
You can do “zfs style raid things” with btrfs, but there are way too many reports of it ending badly for my tastes. Something-something about “write hole”.