The server does not yet support FUA for direct IO #2
Description
Forced Unit Access is a flag that can be set on mutating commands to guarantee that the data is directly written to persistent storage. To support it, we might want to introduce a FUA-variant of nbd.Device as an optional interface and then advocate support via server flags.
Relevant spec values:
- NBD_FLAG_SEND_FUA
- NBD_CMD_FLAG_FUA