Hi Martin, On Wed, Apr 22, 2020 at 5:40 PM Martin Wilck <mwilck@xxxxxxxx> wrote: > > On Wed, 2020-04-22 at 16:00 +0200, Gioh Kim wrote: > > > > One question. > > Is it possible for multipathd to generate an event for removing a > > map? > > I am looking into the source code, ev_add_path and some functions > > related to add a path, > > but it looks like it does not generate any event. > > I guess you mean an uevent. These events are created by the kernel when > multipath creates or reloads maps. multipathd normally doesn't trigger > the events directly. But there are some cases where multipathd > basically runs the equivalent of "udevadm trigger -c change" on either > maps or paths. Search the code for "trigger" for details. > > There are also device mapper events which are created by the kernel for > certain state changes of dm devices. Again, multipathd only receives > such events. > > Regards > Martin > > > I am making an environment to capture log for uevent as you said. Meanwhile I found something weird: "orphan path, waiting for create to complete" what is this message? I guess the second added path was not registered when I executed "multipathd add path" at this moment. I guess there would be some time delay for the second path to be included in the topology. Am I right? If I am right, could I make "multipathd add path" return only after everything is completely finished? Below is a log message from my test. * multipathd add path sdc * multipathd add path sdm * multipathd show topology --> There is no sdm! My test failed. I would like to check sdm here. * multipathd show topology --> Now sdm is included after some mili-second. Apr 23 11:38:25 ib1 multipathd[2132]: sdc: add path (operator) Apr 23 11:38:25 ib1 multipathd[2132]: sdc: open node: /dev/sdc Apr 23 11:38:25 ib1 multipathd[2132]: sdc: mpp is null Apr 23 11:38:25 ib1 multipathd[2132]: sdc: creating new map Apr 23 11:38:25 ib1 multipathd[2132]: sdc: open node: /dev/sdc Apr 23 11:38:25 ib1 multipathd[2132]: sdc: domap with mpp->action=6 Apr 23 11:38:25 ib1 multipathd[2132]: 360000000000000000000000000000000: load table [0 204800 multipath 1 retain_attached_hw_handler 0 1 1 service-time 0 1 1 8:32 1] Apr 23 11:38:25 ib1 multipathd[2132]: 360000000000000000000000000000000: event checker started Apr 23 11:38:25 ib1 multipathd[2132]: sdc [8:32]: path added to devmap 360000000000000000000000000000000 Apr 23 11:38:25 ib1 multipathd[2132]: sdm: add path (operator) Apr 23 11:38:25 ib1 multipathd[2132]: sdm: orphan path, waiting for create to complete Apr 23 11:38:25 ib1 multipathd[2132]: cli[1]: Reply [238 bytes] Apr 23 11:38:25 ib1 multipathd[2132]: reply: [create: 360000000000000000000000000000000 dm-6 SCST_BIO,ltp-pserver3500 Apr 23 11:38:25 ib1 multipathd[2132]: size=100M features='1 retain_attached_hw_handler' hwhandler='0' wp=rw Apr 23 11:38:25 ib1 multipathd[2132]: `-+- policy='service-time 0' prio=1 status=enabled Apr 23 11:38:25 ib1 multipathd[2132]: `- 4:0:0:0 sdc 8:32 active ready running Apr 23 11:38:25 ib1 multipathd[2132]: ] Apr 23 11:38:25 ib1 multipathd[2132]: 360000000000000000000000000000000: load table [0 204800 multipath 1 retain_attached_hw_handler 0 1 1 service-time 0 2 1 8:32 1 8:192 1] Apr 23 11:38:25 ib1 multipathd[2132]: cli[1]: Reply [274 bytes] Apr 23 11:38:25 ib1 multipathd[2132]: reply: [360000000000000000000000000000000 dm-6 SCST_BIO,ltp-pserver3500 Apr 23 11:38:25 ib1 multipathd[2132]: size=100M features='1 retain_attached_hw_handler' hwhandler='0' wp=rw Apr 23 11:38:25 ib1 multipathd[2132]: `-+- policy='service-time 0' prio=1 status=enabled Apr 23 11:38:25 ib1 multipathd[2132]: |- 4:0:0:0 sdc 8:32 active ready running Apr 23 11:38:25 ib1 multipathd[2132]: `- 5:0:0:0 sdm 8:192 active ready running Apr 23 11:38:25 ib1 multipathd[2132]: ] -- Gioh Kim Cloud server kernel maintainer Quality Management (IONOS Cloud) 1&1 IONOS SE | Greifswalder Str. 207 | 10405 Berlin | Germany Phone: +49 176 26978962 E-mail: gi-oh.kim@xxxxxxxxxxxxxxx | Web: www.ionos.de Hauptsitz Montabaur, Amtsgericht Montabaur, HRB 24498 Vorstand: Dr. Christian Böing, Hüseyin Dogan, Dr. Martin Endreß, Hans-Henning Kettler, Arthur Mai, Matthias Steinberg, Achim Weiß Aufsichtsratsvorsitzender: Markus Kadelke Member of United Internet Diese E-Mail kann vertrauliche und/oder gesetzlich geschützte Informationen enthalten. 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