btrfs device scan returns nothing?

What am I doing wrong?

sudo btrfs device scan

Scanning for Btrfs filesystems
[silence]

But I'm running on btrfs now:

--- /etc/fstab
UUID=7246327b-1905-4fe2-9b6b-b9376017264f / btrfs
subvol=root 1 1
UUID=2c04be93-34c1-4016-ba41-60fd9fd90616 /boot ext4
defaults 1 2
UUID=7246327b-1905-4fe2-9b6b-b9376017264f /home btrfs
subvol=home 1 2
...

Those who fail to understand recursion are doomed to repeat it

Nothing wrong -- that's what it's meant to do.

It tells the kernel about the filesystems it finds, not the
user. If you want to do a scan and show the filesystems on the current machine, btrfs fi show is the tool you need.

Hugo.

Hugo Mills             | We don't just borrow words; on occasion, English has
hugo@... carfax.org.uk | pursued other languages down alleyways to beat them
http://carfax.org.uk/  | unconscious and rifle their pockets for new
PGP: E2AB1DE4          | vocabulary.                           James D. Nicoll