I know how to use pv and pvc, and mount on pods. I just curious about why we can't run mount command to mount a testfile, raw block to a mountpoint. I tried to assign a raw block to a pod and format to ext4 and mount it with output "....read-only". I also tried dd a file and format that, still can't mount.

I just wonder if that relate to the linux mount namespace. I really appriciate if someone can help on this because I can't find any materials related to it(maybe I missed).