> Isn't one of the difficulties the inability to decide when the I/O error is transient (e.g. running out of space with thin provisioning) vs. permanent (e.g.

> Isn't one of the difficulties the inability to decide when the I/O error is transient (e.g. running out of space with thin provisioning) vs. permanent (e.g. drive eaten by a velociraptor)? I don't really think so. The thin provisioning thing really is just a series of bugs in the kernel, because the thin provisioning code just didn't (and maybe doesn't), bubble up errors with enough information. Even if errors are transient, at some point the decision to shut down the FS on a device with enough transient errors is a much better fix than throwing away data.