Keith, > Your change looks fine, though it sounds odd that md raid is changing > queue_limit values outside the limits_lock. The stacking limits should > have set the md device to 0 if one of the member drives doesn't > support write_zeroes, right? SCSI can't reliably detect ahead of time whether a device supports WRITE SAME. So we'll issue a WRITE SAME command and if that fails we'll set the queue limit to 0. So it is "normal" that the limit changes at runtime. I'm debugging a couple of other regressions from the queue limits shuffle so I haven't looked into this one yet. But I assume that's what's happening. -- Martin K. Petersen Oracle Linux Engineering