Onboarding a cinder node which is intended to be used with shared storage backend using the pf9-express tool causes the LVM role to be applied instead by default as per the link below.
I think this is expected. LVM is required for the iSCSI connection in order to leverage the shared storage path. Otherwise, you would need some other Cinder backend to support this.
Onboarding a cinder node which is intended to be used with shared storage backend using the pf9-express tool causes the LVM role to be applied instead by default as per the link below.
https://github.com/platform9/express/blob/ff4878bf3f96176d48360fd01619b56a03584c83/pf9-express.yml#L127