On Fri, 2018-11-16 at 14:28 -0500, Mike Snitzer wrote: > On Fri, Nov 16 2018 at 5:17am -0500, > Christoph Hellwig <hch@xxxxxx> wrote: > > > On Fri, Nov 16, 2018 at 11:06:32AM +0100, Hannes Reinecke wrote: > > > Ok, so would you be happy with making ANA support configurable? > > > > I've looked a bit over the whole situation, and what I think we > > need > > to do is: > > > > a) warn if we see a ANA capable device without multipath support > > so people know it is not going to work properly. > > I disagree with your cynicism but v2 of this patch now emits a > warning > accordingly. > > > b) deprecate the multipath module option. It was only intended as > > a migration for any pre-existing PCIe multipath user if there > > were any, not to support any new functionality. So for 4.20 > > put in a patch that prints a clear warning when it is used, > > including a link to the nvme list, and then for 4.25 or so > > remove it entirely unless something unexpected come up. > > You rejected the idea of allowing fine-grained control over whether > native NVMe multipathing is enabled or not on a per-namespace basis. > All we have is the coarse-grained nvme_core.multipath=N knob. Now > you're forecasting removing even that. Please don't do that. > > > This whole drama of optional multipath use has wasted way too much > > of everyones time already. > > It has wasted _way_ too much time. > > But the drama is born out of you rejecting that we need to preserve > multipath-tools and dm-multipath's ability to work across any > transport. You don't need to do that work: Hannes, myself and others > have always been willing and able -- if you'd let us. > > IIRC it was at 2016's LSF in Boston where Ewan Milne and I had a > face-to-face conversation with you in the hallway track where you > agreed > that ANA support would be activated if the capability was advertised > by > the target. The model we discussed is that it would be comparable to > how ALUA gets enabled during SCSI LUN discovery. > > I hope you can see your way forward to be more accommodating now. > Especially given the proposed changes are backed by NVMe standards. > > Please, PLEASE take v2 of this patch.. please? ;) > > Thanks, > Mike I am begging you take it too please Thanks Laurence
