[CentOS] lvm snapshot

Creating snapshot:

[root at lvmtest ~]# lvcreate -L5G -s -n root_snap /dev/centos/root
   Reducing COW size 5,00 GiB down to maximum usable size 2,94 GiB.
   Logical volume "root_snap" created.
[root at lvmtest ~]# lvs
   LV        VG     Attr       LSize Pool Origin Data%  Meta%  Move  
Log Cpy%Sync Convert
   root      centos owi-aos--- 2,93g
   root_snap centos swi-a-s--- 2,94g      root   0,00
   swap      centos -wi-ao---- 1,00g

--- reboot ---

dracut shell (missing /dev/centos/root)

cat proc/cmdline:
BOOT_IMAGE=/vmlinuz-3.10.0-229.20.1.el7.x86_64
root=/dev/mapper/centos_root ro rd.lvm.lv=centos/root
rd.lvm.lv=centos/swap crashkernel=auto rhgb quiet LANG=de_DE.UTF-8
systemd.debug

ls /dev/mapper:
centos-swap control

Grüße

Axel