On Mon, Feb 27, 2017 at 09:49:59AM -0500, Les Stroud wrote: > After a period of a couple of weeks with one of our test instances having this problem every other day, they were all nice enough to operate without an issue for 9 days. It finally reoccurred last night on one of the machines. > > It exhibits the same symptoms and the call traces look as they did previously. This particular instance is configured with a deadline scheduler. I was able to capture the inflight you requested: > > $ cat /sys/block/xvd[abcde]/inflight > 0 0 > 0 0 > 0 0 > 0 0 > 0 0 > > I’ve had this happen on instances with the deadline scheduler and the noop scheduler. At this point, I have not had this happen on an instance that is noop and the raid filesystem (ext4) is mounted with nobarrier. The instances with noop/nobarrier have not been running long enough for me to make any sort of conclusion that it works around the problem. Frankly, I’m not sure I understand the interaction between ext4 barriers and raid0 block flushes well enough to theorize whether it should or shouldn’t make a difference. If nobarrier, ext4 doesn't send flush request. > Does any of this help with identifying the bug? Is there anymore information I can get that would be useful? Unfortunately I can't find anything fishing. Does the xcdx disk correctly handle flush request? For example, you can do the same test with a single such disk and check if anything wrong. Thanks, Shaohua -- 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
