>>>>> "Jens" == Jens Axboe <ax...@kernel.dk> writes:
>> I think we should fix sd.c to only send WRITE SAME if either of the >> variants are explicitly listed as supported through REPORT SUPPORTED >> OPERATION CODES, or maybe through a whitelist if there are important >> enough devices. Jens> Yep I hate it too. But the reason it's assumed on is that there is essentially no heuristic that works. Just like we assume that READ always works. Out of the ~200 devices I have access to in the lab: - 100% of the SAS/FC disk drives and SSDs support WRITE SAME - Only 2 out of about 50 different drive models support RSOC - About half of the arrays support WRITE SAME(10/16) - None of the arrays I have support RSOC So even if we were to entertain using RSOC for "enterprise" transport classes (which I concur would be nice for other reasons), it wouldn't solve the WRITE SAME problem... -- Martin K. Petersen Oracle Linux Engineering
