Hi Neil, I think we have some bad side effects with this patch: commit 199dc6ed5179251fa6158a461499c24bdd99c836 Author: NeilBrown <neilb@xxxxxxxx> Date: Mon Aug 3 13:11:47 2015 +1000 md/raid0: update queue parameter in a safer location. When a (e.g.) RAID5 array is reshaped to RAID0, the updating of queue parameters (e.g. max number of sectors per bio) is done in the wrong place. It should be part of ->run, but it is actually part of ->takeover. This means it happens before level_store() calls: blk_set_stacking_limits(&mddev->queue->limits); Running the '03r0assem' test suite fills my kernel log with output like below. Yi Zhang also had issues where writes failed too. robably something we need to resolve for 4.2-final or revert the offending patch. Cheers, Jes md: bind<loop0> md: bind<loop1> md: bind<loop2> md/raid0:md2: md_size is 116736 sectors. md: RAID0 configuration for md2 - 1 zone md: zone0=[loop0/loop1/loop2] zone-offset= 0KB, device-offset= 0KB, size= 58368KB md2: detected capacity change from 0 to 59768832 bio too big device loop0 (296 > 255) bio too big device loop0 (272 > 255) bio too big device loop1 (672 > 255) bio too big device loop1 (352 > 255) bio too big device loop2 (1024 > 255) bio too big device loop0 (672 > 255) bio too big device loop1 (256 > 255) bio too big device loop2 (288 > 255) bio too big device loop2 (736 > 255) bio too big device loop0 (288 > 255) bio too big device loop2 (256 > 255) bio too big device loop2 (368 > 255) bio too big device loop0 (488 > 255) bio too big device loop0 (360 > 255) bio too big device loop0 (256 > 255) bio too big device loop1 (288 > 255) bio too big device loop1 (736 > 255) bio too big device loop2 (288 > 255) bio too big device loop1 (256 > 255) bio too big device loop1 (512 > 255) bio too big device loop2 (856 > 255) bio too big device loop2 (256 > 255) bio too big device loop0 (288 > 255) bio too big device loop0 (736 > 255) bio too big device loop1 (288 > 255) bio too big device loop0 (256 > 255) bio too big device loop0 (512 > 255) bio too big device loop1 (856 > 255) bio too big device loop1 (256 > 255) bio too big device loop2 (288 > 255) bio too big device loop2 (736 > 255) md2: detected capacity change from 59768832 to 0 md: md2 stopped. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html