Hi Martin, I sent an updated patch to support coalesce heterogenous paths by inserting udev rules file as suggested by you in this original patch a few days ago. I have tested this solution and it works on the sd/nvme disk at least. Here is the updated patch using udev solution: [PATCH] multipath-tools: support for coalescing heterogenous paths https://www.redhat.com/archives/dm-devel/2017-August/msg00213.html What do you think of the new patch? Please let me know if it is convenient to you . Best Wishes, Guan Junxiong On 2017/7/24 15:41, Guan Junxiong wrote: > Hello Martin, > Thanks for your comments. Please find my comments inline. > > On 2017/7/21 18:21, Martin Wilck wrote: >> Hello Guan, >> >> On Fri, 2017-07-21 at 13:07 +0800, Guan Junxiong wrote: >>> This three patches support coalescing heterogenous paths by >>> referencing >>> another path identifier. This is useful in the scenario of migrating >>> data >>> for heterogenous arrays without interrupting uplayer transaction. >>> ... >> Anyway, I'm wondering if multipath configuration is the right place to >> apply a "fake" configuration like this. Have you considered doing this >> on the udev level? Udev has the advantage that udev immediately sees >> added or modified rules files. So if you want to pretend temporarily >> that sda is indeed the same disk as sdd, you could insert appropriate >> temporary udev rules to do that. This would have the additional benefit >> that not only multipathd sees the mangled WWID but also the rest of the >> system (IOW, multipathd's view of the system would be consistent with >> the world outside multipathd). > > "udev level " solution is a good thing. Thanks. > I still have a doubt whether a udev rules is enough to meet this fake configuration. > IOW ,in addition to udev rules , do we still have to write a C program to fetch > sth . I will write a demo of this to see whether it has problems or not. > > Regards, > Guan Junxiong > > >> Postponing a detailed technical patch review until these questions are >> clarified. >> >> Regards, >> Martin >> -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
