Getting this?

bash: pvchange: command not found
bash: pvck: command not found
bash: pvcreate: command not found
bash: pvdisplay: command not found
bash: pvmove: command not found
bash: pvs: command not found
bash: pvscan: command not found

Means you might have used su. Just do su - or do a proper login, so your $PATH is set correctly.