On Mon, Apr 16 2018 at 4:52pm -0400, Gruher, Joseph R <joseph.r.gruher@xxxxxxxxx> wrote: > Hi everyone- > > I'm doing some testing with the native NVMe multipath support in an > NVMeoF environment. In Ubuntu with kernel 4.15.15 it seems to be > enabled by default and "just works" without taking any steps to set it > up. If I connect the same namespace from my target to my initiator > using two different network paths it results in a single namespace on > the initiator. Then I can fail either network path and still run IO > to the namespace. > > I'd like to now set up dm-multipath for comparison. It looks like > I'll need to disable the native NVMe multipath support to do this, > otherwise I can't connect the same namespace via two paths and have it > show up on the initiator as two separate namespaces for dm-multipath > to use. Is there an quick and easy way to do disable the native NVMe > multipath support, or is rebuilding the kernel with > CONFIG_NVME_MULTIPATH=N the only option? Current upstream kernel needs to be rebuilt with CONFIG_NVME_MULTIPATH=N AFAIK Keith Busch is working on a patch to fix crashes when multiple namespaces are created with an nvme_core that is compiled for multipath but disabled at module load, e.g.: modprobe nvme_core multipath=N (or nvme_core.multipath=N on kernel commandline) See: http://lists.infradead.org/pipermail/linux-nvme/2018-April/016765.html FYI, when testing DM multipath ontop of NVMe you should use dm-multipath's table argument: queue_mode=bio -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
