Unable to create QCOW2 volume under LVM2

[jonc]

I added more internal storage as LVM2 to a Proxmox host. When I try to create a VM and select this storage the only option on offer is to use RAW, I'm unable to select QCOW2, the dropdown is ghosted out.
Is there a limitation with regards to VM's sitting on an LVM2 drive?

 

[dietmar]

Qcow2 only works one file systems, so it is not possible to use that format with LVM2.