[root@nas04 ~]# drbdadm create-md drbd_nfs
pvs stderr:        /dev/sdb1: Skipping (regex)
pvs stderr:  Failed to read physical volume "/dev/sdb1"
pvs stderr:      Unlocking /var/lock/lvm/P_global
pvs stderr:        _undo_flock /var/lock/lvm/P_global

md_offset 2199020343296
al_offset 2199020310528
bm_offset 2198953201664

Found LVM2 physical volume signature
  2147415236 kB left usable by current configuration
Could not determine the size of the actually used data area.

Device size would be truncated, which
would corrupt data and result in
'access beyond end of device' errors.
If you want me to do this, you need to zero out the first part
of the device (destroy the content).
You should be very sure that you mean it.
Operation refused.

Command 'drbdmeta 0 v08 /dev/sdb1 internal create-md' terminated with exit code 40