Hi Mike, Mike Christie wrote: > Hannes Reinecke wrote: >> Hi Mike, >> >> michaelc@xxxxxxxxxxx wrote: >>> From: Mike Christie <michaelc@xxxxxxxxxxx> >>> >>> If you have a mixed environment of clarriions, where some >>> support ALAU and some support PNR, what do you put in >>> your multipath.conf? With this patch you do not have to worry about >>> it. If those modules are loaded before dm-mpath, then they >>> will have attached to the correct devices based on inquiry, alua >>> commands >>> and parsing of data buffers (for example in scsi_dh_emc's alua check). >>> There is no need for the user to set that info in the multipath.conf. >>> And in general since all scsi_dh_modules will attach to the devices >>> they work for, we do not need to have users specific this. >>> >> No. The problem here is the hardware table from scsi_dh is compiled >> in and cannot be changed from userland. The multipath.conf OTOH >> is purely user-defined and, what's more, the user might have a valid >> reason for modifying it. >> (EG EMC Clariion can well be run in PNR mode even though ALUA is >> active, or the user might want to try ALUA on any as-of-yet unknown >> devices) > > Ah. I misread the code and misunderstood the compat mode. I thought > scsi_dh_emc was failing the attach when ALUA support was detected. > >> >> So _not_ allowing multipath to override the device handler setting >> will just add to the confusion and makes error tracking even more >> difficult. >> >> So I would prefer the attached patch, it even save to touch >> device handler code at all. >> > > Thanks. I think this will work for me. > > Are you going to push this for 2.6.30? Well, yes, I could. However, I'm still waiting for agk to push the request-based multipath patches; I've got quite some updates here for multipathing which are done with request-based multipath in place; disentangling them will be quite time consuming (and pointless). But this one, sure. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
