On Tue, 27 Aug 2013 11:31:41 +0200, Stefan Priebe - Profihost AG wrote:

For all my bcache devices blkid returns:

# /sbin/blkid -o udev /dev/sdd1
ID_FS_UUID=6937d2e6-c8e3-4590-954b-65937fc23a52
ID_FS_UUID_ENC=6937d2e6-c8e3-4590-954b-65937fc23a52
ID_FS_TYPE=xfs

What's wrong here? All disks have XFS on top of bcache running.

The udev rules were changed to reject bcache devices with a
pre-existing superblock (xfs in your case).

This was done to fail early when there's a risk of exposing an
unsynchronised backend device, which would be a bad thing™.

You can remove the stray superblocks with wipefs.