Darrick, [Anchor] > What happens if you anchor and then try to read the results? IO > error? Depends on the device. Typically you get the same results as UNMAP. Anchoring is essentially a way to preallocate blocks on a thinly provisioned device. If you then run out of actual storage capacity you won't get a write failure writing to those LBAs. It is intended to protect block ranges that do not tolerate write failures (journals, metadata). -- Martin K. Petersen Oracle Linux Engineering
