MY virtual machine not work when restart

Hello all,
Help~~ I had met a problem:
when I restart my virtual machine. my machine not start .My system disk is ceph-rbd, is version 17.2.6. I find rbd image first 512byte has modified. so I dont down why? now my qemu version 1:6.2+dfsg-2ubuntu6.12 . Is it a bug? Has anyone encountered this?