I consistently hit this one with the following scenario : * multipathd runs * map configured with multibus policy in the config file * dmsetup remove the map * multipath -p failover here multipath load the failover map, then signals the daemon, which promptly runs multipath whichs load a multibus map. and BUG. Also I would like to know if it's expected behaviour the DM_WAIT ioctl isn't given a chance to unblock upon DM_REMOVE, as it would ease the thread maintenance in multipathd if it was. Regards, cvaroqui Unable to handle kernel paging request at ffffc20000057080 RIP: <ffffffff8804fb0c>{:dm_multipath:trigger_event+4} PGD 4dac067 PUD 4dab067 PMD 4daa067 PTE 0 Oops: 0000 [1] SMP CPU 0 Modules linked in: dm_round_robin iscsi_tcp iscsi_if af_packet ipv6 smbfs tsdev mousedev evdev i2c_amd756 i2c_core hw_random amd74xx ohci_hcd tg3 ide_generic ide_cd ide_core cdrom ext3 jbd mbcache sd_mod unix dm_multipath dm_mod mptscsih scsi_mod mptbase Pid: 6, comm: events/0 Not tainted 2.6.12-rc1 RIP: 0010:[<ffffffff8804fb0c>] <ffffffff8804fb0c>{:dm_multipath:trigger_event+4} RSP: 0018:ffff810004f1be60 EFLAGS: 00010247 RAX: ffffc20000057080 RBX: ffff8100f3e75f00 RCX: ffff810004f1bed0 RDX: ffff810004ef9818 RSI: 0000000000000292 RDI: ffff8100f3e75e00 RBP: ffff8100f3e75f08 R08: ffff810004f1a000 R09: 0000000000000001 R10: 0000000000000000 R11: ffffffff8011b64f R12: ffff810004ef9800 R13: 0000000000000292 R14: ffff8100f3e75e00 R15: ffffffff8804fb08 FS: 00002aaaab0164a0(0000) GS:ffffffff803d6200(0000) knlGS:000000005577c560 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: ffffc20000057080 CR3: 00000000f2f35000 CR4: 00000000000006e0 Process events/0 (pid: 6, threadinfo ffff810004f1a000, task ffff810004df2730) Stack: ffffffff80142bcc ffff810004ef9840 ffff810004ef9818 ffff810004ef9828 ffffffffffffffff 0000000000000001 0000000000000000 ffffffff8012d734 0000000000010000 0000000000000000 Call Trace:<ffffffff80142bcc>{worker_thread+501} <ffffffff8012d734>{default_wake_function+0} <ffffffff8012d782>{__wake_up_common+64} <ffffffff8012d734>{default_wake_function+0} <ffffffff801429d7>{worker_thread+0} <ffffffff80146ce5>{kthread +218} <ffffffff8010f443>{child_rip+8} <ffffffff80146c0b>{kthread+0} <ffffffff8010f43b>{child_rip+0} Code: 48 8b 38 e9 ab 18 ff ff 48 83 ec 18 48 85 f6 48 89 f0 48 89 RIP <ffffffff8804fb0c>{:dm_multipath:trigger_event+4} RSP <ffff810004f1be60> CR2: ffffc20000057080 -- christophe varoqui <christophe.varoqui@xxxxxxx>