On 09/15/2017 12:00 PM, Guan Junxiong wrote: > > > On 2017/9/15 14:30, Hannes Reinecke wrote: >> The NVMe path states 'resetting' and 'reconnecting' indicate that >> the controller could not talk to the namespace, which translates >> into a path down state, not a path pending state. >> Path pending should only be used for short lived intermediate states >> like 'new' or 'deleting'. > I agree with the statements --Path pending should only be used for short > lived intermediate states. But it's better to schedule path state checking > so soon as possible in the next second for "resetting" and "reconnecting" > states because those two states is transient in a short time. > How about introducing a new state for multipath: PATH_TRANSITING to distinguish > PATH_PENDING? > I beg to disagree. 'reconnecting' is telling us that the controller is trying to reconnect to the namespace, which will continue until KATO expires IIRC. Which can well be several seconds, plus this actually _is_ a path down state (path down signals that the transport layer lost connection to the remote system, which is exactly what this error is). And 'resetting' is the controller entering reset after KATO expired, so most definitely a path down event. And this took several minutes on the machine I've tested with, so it's anything but fast. Or to put it another way round: if we treat these events as PATH_PENDING, which events would then signal a PATH_DOWN? We only have new live reconnecting resetting deleting dead to choose from ... Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
