The most likely cause appears to be a path‑translation bug in the CLI when handling a remote pool spec. We have the following work‑arounds in place: • Copy the destination image locally first, then run export‑diff. • Use `rbd diff` + manual transfer. • Map the remote image as a block device and operate on `/dev/rbdX`.
Please let us know if additional information is needed. rbd-638
We have reproduced RBD‑638 consistently on a test environment (Octopus 15.2.7). The failure occurs only when the destination image lives on a remote pool (accessed via CephFS or a separate cluster). `rbd info` works, but `rbd export‑diff` aborts with “No such file or directory”. The most likely cause appears to be a