** Description changed: + [Impact] + When a volume is attached to a VM in the source compute node through multipath, the related files in /dev/disk/by-path/ are like this stack@ubuntu-server12:~/devstack$ ls /dev/disk/by-path/*24 /dev/disk/by-path/ip-192.168.3.50:3260-iscsi-iqn.1992-04.com.emc:cx.fnm00124500890.a5-lun-24 /dev/disk/by-path/ip-192.168.4.51:3260-iscsi-iqn.1992-04.com.emc:cx.fnm00124500890.b4-lun-24 The information on its corresponding multipath device is like this stack@ubuntu-server12:~/devstack$ sudo multipath -l 3600601602ba03400921130967724e411 3600601602ba03400921130967724e411 dm-3 DGC,VRAID size=1.0G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw |-+- policy='round-robin 0' prio=-1 status=active | `- 19:0:0:24 sdl 8:176 active undef running `-+- policy='round-robin 0' prio=-1 status=enabled `- 18:0:0:24 sdj 8:144 active undef running But when the VM is migrated to the destination, the related information is like the following example since we CANNOT guarantee that all nodes are able to access the same iSCSI portals and the same target LUN number. And the information is used to overwrite connection_info in the DB before the post live migration logic is executed. stack@ubuntu-server13:~/devstack$ ls /dev/disk/by-path/*24 /dev/disk/by-path/ip-192.168.3.51:3260-iscsi-iqn.1992-04.com.emc:cx.fnm00124500890.b5-lun-100 /dev/disk/by-path/ip-192.168.4.51:3260-iscsi-iqn.1992-04.com.emc:cx.fnm00124500890.b4-lun-100 stack@ubuntu-server13:~/devstack$ sudo multipath -l 3600601602ba03400921130967724e411 3600601602ba03400921130967724e411 dm-3 DGC,VRAID size=1.0G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw |-+- policy='round-robin 0' prio=-1 status=active | `- 19:0:0:100 sdf 8:176 active undef running `-+- policy='round-robin 0' prio=-1 status=enabled `- 18:0:0:100 sdg 8:144 active undef running As a result, if post live migration in source side uses <IP>, <IQN> and <TARGET LUN Number> to find the devices to clean up, it may use 192.168.3.51, iqn.1992-04.com.emc:cx.fnm00124500890.a5 and 100. However, the correct one should be 192.168.3.50, iqn.1992-04.com.emc:cx.fnm00124500890.a5 and 24. Similar philosophy in (https://bugs.launchpad.net/nova/+bug/1327497) can be used to fix it: Leverage the unchanged multipath_id to find correct devices to delete. + + [Test Case] + + Live migrate an instance which uses iSCSI multipath. Verify the correct + target is removed on source hypervisor. + + [Regression Potential] + + Not much, its included in the next release (Juno). The change introduces + a check to use a field already used by fiber multipath connections which + was not used by iscsi multipath code path on cleanup. If it fails it + would keep remaining behavior of not cleaning up iscsi sessions/paths.
** Tags removed: in-stable-juno ** Tags removed: verification-needed ** Tags added: in-stable-juno verification-done -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1357368 Title: Source side post Live Migration Logic cannot disconnect multipath iSCSI devices cleanly To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1357368/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
