Tips & notes about btrfs

[Note] Df Command Doesn't Show Enough Output About Btrfs Filesystems


If you use df with options like -i, you may see empty output or not enough information about the disks.


Use btrfs command and its utilities to manipulate Btrfs partitions:

sudo btrfs filesystem df /

[Problem] Programs Suddenly Stop Working/Crash


Sometimes, you may encounter different problems on distributions running on Btrfs filesystem because of "no disk space" error. Although you may have some free disk space, you would notice that a lot of applications and programs are suddenly crashing.

Firefox, Steam, Zypper, Chromium and a lot of other apps may just stop working suddenly with errors like:

Cannot write file '/var/adm/mount/AP_0xBl0ihT/repodata/repomd.xml'.

WARNING: Unix error 28 during operation move on file /myuser/.mozilla/firefox/xofrqlc6.default/saved-telemetry-pings/xxxxxxxx-bbd4-468a-a034-19111020d2ce.tmp (No space left on device)

This is because of a strange bug with some Btrfs installations. The system doesn't recognize that it has free space to use.Causing software to crash instantly when there's not enough space.


As a workaround, you may remove some big files/data from your hard disk in order to get everything to work again.

[Problem] Btrfs Doesn't Support Swap File


This is a known problem with Btrfs. Unfortunately, it doesn't have a solution. You'll need to create a separated swap partition in order to use it with a Btrfs filesystem.