Bart, > In my opinion there is a contradiction between the above reply and > patch 19/21 of this series. Data written with the SCSI WRITE ATOMIC > command is not guaranteed to survive a power failure. That is not the intent. The intent is to ensure that for any given application block (say 16KB), the application block on media will contain either 100% old data or 100% new data. Always. If a storage device offers no such guarantee across a power failure, then it is not suitable for use by applications which do not tolerate torn writes. That is why the writes-are-atomic-unless-there's-a-problem variant of the values reports in NVMe are of no interest. -- Martin K. Petersen Oracle Linux Engineering