On 10/08/2015 09:44 PM, Benjamin Marzinski wrote: > Ideally, udev will be able to grab the wwid when a path device is > discovered, but sometimes this isn't possible. In these cases, the > best thing that could happen would be for udev to actually get the > information, and add it to its database. This patch makes multipath > retrigger uevents a limited number of times before giving up and > trying to get the information itself. > > There are two configurables that control how it does this, > "retrigger_tries" and "retrigger_delay". The first sets the number of > times it will try to retrigger a uevent to get the wwid, the second > sets the amount of time to wait between retriggers. > > This patch currently only tries reinitializing the path on change events > after multipathd has triggered a change event, and it only tries once > per triggered change event. Now, its possible that other change events > could occur on the device without multipathd tirggering them. As the > patch stands now, it won't try to initialize the device on those. It will, > however still try in the checkerloop, but only after it has finished > retriggering the uevents. We could be much more aggressive here, and assume > that devices that simply won't have a WWID should already be taken care of > by the blacklists, so it would be always a good idea to recheck devices on > change events. What would be ideal is if udev would let us know when it had > problems or timed out when processing a uevent, so we would know if > retriggering the uevent would be useful. > > Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx> > --- Hmm. Yes, this 'udev killing worker after a certain time' is a major pain. And we've tried to work around it, too. With various degrees of success. But I'm not sure if retriggering is a good idea here; we simply have no idea if the failure is legit or not. Can't we work with the udev/systemd folks to add a variable telling us that udev killed the worker? Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage 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
