On Thu, Oct 01, 2009 at 10:55:12AM +0200, John Hughes wrote: > Hannes Reinecke wrote: >> malahal@xxxxxxxxxx wrote: >>> John Hughes [john@xxxxxxxxx] wrote: >>>> I want to turn queue_if_no_path off and use >>>> >>>> polling_interval 5 >>>> no_path_retry 5 >>>> >>>> because I've had problems with things hanging when a lun "vanishes" (I >>>> deleted it from my external raid box). >>>> >>>> But whatever I put in /etc/multipath.conf when I do a "multipath -l" or >>>> "multipath-ll" it shows: >>>> 360024e80005b3add000001b64ab05c87dm-28 DELL ,MD3000 >>>> [size=68G][features=1 queue_if_no_path][hwhandler=1 rdac] >>>> \_ round-robin 0 [prio=3][active] >>>> \_ 3:0:1:13 sdad 65:208 [active][ready] >>>> \_ round-robin 0 [prio=0][enabled] >>>> \_ 4:0:0:13 sdas 66:192 [active][ghost] >>>> >> Which is entirely correct. The 'queue_if_no_path' flag _has_ to >> be set here as we do want to retry failed paths, if only for >> a limited amount of retries. >> >> The in-kernel dm-multipath module should handle the situation correctly >> and switch off the queue_if_no_path flag (= pass I/O errors upwards) >> when the amount of retries is exhausted. > As far as I can tell it retries forever (even with polling_interval 5 and > no_path_retry 5). The mdadm raid10 built on top of the multipath devices > hangs, even /proc/mdstat hangs. > > You're saying that without queue_if_no_path multipath basicly won't work - > mdadm will see I/O errors on multipath devices if a path fails? > If _all_ paths fail. Note the 'no_path' bit :-) Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N�g GF: Markus Rex, HRB 16746 (AG N�g) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
