On Fri, June 26, 2009 10:30 am, Ron Lai wrote: > Hi, > I use mdadm to setup multipath on a box running 2.6.25.14 and I try to > simualte SAN failure by shutting down ports on the switch one by one. > After > I disable the last IO path, the box hangs with the following logs spewed > out > on the console. > > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector 8 > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector 48 to > another IO path > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector > 200015880 to another IO path > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector > 200016408 to another IO path > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector > 200114976 to another IO path > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector 56 > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector > 200015888 > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector > 200016416 > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector > 200114984 > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector 0 to > another IO path > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector 48 to > another IO path > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector > 200015880 to another IO path > Jun 23 14:32:31 localhost kernel: multipath: sdn: redirecting sector > 200016408 to another IO path > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector 8 > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector 56 > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:31 localhost kernel: multipath: sdn2: rescheduling sector > 200015888 > Jun 23 14:32:31 localhost kernel: multipath: only one IO path left and IO > error. > Jun 23 14:32:32 localhost kernel: multipath: sdn2: rescheduling sector > 200016416 > Jun 23 14:32:32 localhost kernel: multipath: sdn: redirecting sector > 200114976 to another IO path > ........ > > > In multipath_error() in /derivers/md/multipath.c the code says that the > last > path never gets marked as faulty hence it keeps retrying. I've tried to > change the code to allow the last path to be marked as faulty and the box > seems to work okay after the failure in the last path. (The kernel spews > out > logs about inode errors. Nevertheless it stops eventually and mdadm shows > that all the paths are marked as faulty.) Will this modification create > problems in other parts of the kernel? Thanks. Probably not, but it is hard to tell unless you post the actual patch. Could you do that please? Thanks, NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
