>>>>> "Hannes" == Hannes Reinecke <hare@xxxxxxx> writes: Hannes> Not quite. XCOPY is optional, and the system works well without Hannes> it. So the exception handling would need to copy things by hand Hannes> to avoid regressions. Or defer to user space. But it's really no different from how we do WRITE SAME which may or may not work. If it fails we fall back to writing zeroes. Hannes> Plus XCOPY requires some elaborate setup, and even if those Hannes> succeeded the array might still fail the command. _And_ there Hannes> is no guarantee that that the XCOPY command is actually faster Hannes> than the manual procedure. It saves the data a roundtrip on the fabric. That itself may be more valuable than a direct bandwidth win if there is concurrent I/O on the wire. -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
