man pvcreate says
pvcreate initializes a PV so that it is recognized as belonging to LVM, and allows the PV to be used in a VG. A PV can be a disk partition, whole disk,meta device, or loopback file.
What is a meta device? Thanks.
In LVM parlance, a meta device is a device created from some other device or set of devices. Examples include devices created by the MD layer (
/dev/md1 etc.), representing aggregated devices, and devices created by LVM itself, representing logical volumes (so it is possible to create a PV from an LV...).