Error relating to /dev/sr0 when calling btrfs fi show /dev/sdxy

Is the error relating to /dev/sr0 relevant to a call to /usr/bin/brtfs?  Why does it show the superfluous output?

% sudo btrfs fi show /dev/sda3
failed to open /dev/sr0: No medium found
Label: 'arch64'  uuid: ab6f9133-a2ce-4c92-97ab-35cdc3c2d2a9
Total devices 1 FS bytes used 2.46GB
devid    1 size 119.00GB used 5.02GB path /dev/sda3

Btrfs v0.20-rc1-253-g7854c8b

I get this on Virtual Box VMs, also with parted. I don't get it with parted or btrfs on baremetal.

Chris Murphy

This fixed it.

http://permalink.gmane.org/gmane.comp.file-systems.btrfs/27129