>>>>> "Tom" == Tom Yan <tom.ty89@xxxxxxxxx> writes: Tom> No I put it in the wrong way. What I meant was "sd vs md". For Tom> example, couldn't the scsi disk driver bind the value it reads from Tom> the VPD to another variable instead of "optimal i/o size", so that Tom> this value would be exclusively for RAID (and other virtual Tom> devices)? Who says that RAID is a virtual device? Hardware RAID controllers as well as SAS, iSCSI and Fibre Channel disk arrays all use the Block Limits VPD to communicate their preferred I/O size and alignment to us. As do enterprise disk drives. We deal with broken devices by blacklisting them. I suggest you try to find a way we can reliably identify your UAS devices. If there is a common pattern, we can entertain adding a workaround. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html