Damien, > Indeed. It is an NVMe M.2 consumer grade SSD. Nothing fancy. If you > look at nvme/host/core.c nvme_update_disk_info(), you will see that > io_opt is set to the block size... This is probably abusing this > limit. So I guess the most elegant fix may be to have nvme stop doing > that ? Yeah, I'd prefer for io_opt to only be set if the device actually reports NOWS. The purpose of io_min is to be the preferred lower I/O size boundary. One should not submit I/Os smaller than this. And io_opt is the preferred upper boundary for I/Os. One should not issue I/Os larger than this value. Setting io_opt to the logical block size kind of defeats that intent. That said, we should probably handle the case where the pbs gets scaled up but io_opt doesn't more gracefully. -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
