[linux-lvm] devices/dir configuration option in /etc/lvm/lvm.conf can be edited?

[Gang He]

Hello List,

By default, devices/dir configuration option in /etc/lvm/lvm.conf is "=/dev".
But, if I edit this configuration option, e.g. dir = "/dev/lvm", then lvcreate command will fail.

sles12sp4-node:/dev # lvcreate -L2G -ay -n testlv vgdata
  /dev/lvm/vgdata/testlv: not found: device not cleared
  Aborting. Failed to wipe start of new LV.

I am using lvm 2.02.183(or 180), this option can be edit individually? 
or any other option will affect this option, then lead to lvcreate failure.

Thanks
Gang