@Omer SAVAS, please rather open up new posts for issues that are not like the on of the OP.
And for your issue, the content type 'disk image, container' is not allowed on CephFS. This is due to RBD being the better native support for disk images on Ceph and the low performance on small writes on CephFS. This makes it more ideal to store backup, container templates and ISOs.
Sorry. Thank you very much.