Hello, all I'm testing the DM multipath. I use the packages as follows: kernel 2.6.14.2 device-mapper.1.01.05 multipath-tools-0.4.6 udev-058-1 I created the dm device as: create: 3600d0230006927de000001618fecaf00 [size=476 GB][features="0"][hwhandler="0"] \_ round-robin 0 [prio=1] \_ 0:0:0:0 sda 8:0 [undef] [ready] \_ round-robin 0 [prio=1] \_ 1:0:0:0 sdb 8:16 [undef] [ready] Then, I tried the command: dd if=/dev/dm-0 of=/dev/null I saw only the device /dev/sda was readed. It's OK. but when I pull out the HBA which related to /dev/sdb for about 1 minute,and then plug it in again, the kernel paniced. the messages are as follows: Dec 22 05:25:07 nd02 kernel: qla2300 0000:07:01.1: LIP reset occured (f823). Dec 22 05:25:07 nd02 kernel: qla2300 0000:07:01.1: LIP occured (f823). Dec 22 05:25:07 nd02 kernel: qla2300 0000:07:01.1: LOOP DOWN detected (2). Dec 22 05:25:42 nd02 kernel: rport-1:0-1: blocked FC remote port time out: removing target Dec 22 05:25:42 nd02 multipathd: 8:16: readsector0 checker reports path is down Dec 22 05:25:42 nd02 multipathd: checker failed path 8:16 in map 3600d0230006927de000001618fecaf00 Dec 22 05:25:42 nd02 kernel: device-mapper: dm-multipath: Failing path 8:16. Dec 22 05:25:42 nd02 multipathd: 3600d0230006927de000001618fecaf00: remaining active paths: 1 Dec 22 05:25:43 nd02 multipathd: remove sdb path checker Dec 22 05:25:43 nd02 kernel: Synchronizing SCSI cache for disk sdb: Dec 22 05:25:43 nd02 kernel: FAILED Dec 22 05:25:43 nd02 kernel: status = 0, message = 00, host = 1, driver = 00 Dec 22 05:26:12 nd02 kernel: <6>qla2300 0000:07:01.1: LIP reset occured (f8f7). Dec 22 05:26:12 nd02 kernel: qla2300 0000:07:01.1: LIP occured (f8f7). Dec 22 05:26:12 nd02 kernel: qla2300 0000:07:01.1: LOOP UP detected (2 Gbps). Dec 22 05:26:13 nd02 kernel: Vendor: TOYOU Model: NetStor DA9220F Rev: 342R Dec 22 05:26:13 nd02 kernel: Type: Direct-Access ANSI SCSI revision: 03 Dec 22 05:26:13 nd02 kernel: SCSI device sdc: 999950336 512-byte hdwr sectors (511975 MB) Dec 22 05:26:13 nd02 kernel: SCSI device sdc: drive cache: write back Dec 22 05:26:13 nd02 kernel: SCSI device sdc: 999950336 512-byte hdwr sectors (511975 MB) Dec 22 05:26:14 nd02 kernel: SCSI device sdc: drive cache: write back Dec 22 05:26:14 nd02 kernel: sdc: Dec 22 05:26:14 nd02 kernel: Attached scsi disk sdc at scsi1, channel 0, id 0, lun 0 Dec 22 05:26:14 nd02 kernel: Attached scsi generic sg1 at scsi1, channel 0, id 0, lun 0, type 0 Dec 22 05:26:14 nd02 scsi.agent[4098]: disk at /devices/pci0000:00/0000:00:02.0/0000:05:1d.0/0000:07:01.1/host1/rport-1:0-1/target1:0:0/1:0:0:0 --------------------->> All right above here. Dec 22 05:26:14 nd02 kernel: Vendor: TOYOU Model: NetStor DA9220F Rev: 342R Dec 22 05:26:14 nd02 kernel: Type: Direct-Access ANSI SCSI revision: 03 Dec 22 05:26:14 nd02 kernel: error 1 Dec 22 05:26:14 nd02 kernel: scsi: Unexpected response from host 1 channel 0 id 0 lun 0 while scanning, scan aborted Dec 22 05:26:14 nd02 kernel: Badness in kref_get at lib/kref.c:32 Dec 22 05:26:14 nd02 kernel: [<c01d9c6a>] kref_get+0x3f/0x41 Dec 22 05:26:14 nd02 kernel: [<c01d92e0>] kobject_get+0x17/0x1e Dec 22 05:26:14 nd02 kernel: [<c019d896>] sysfs_getlink+0x38/0xfa Dec 22 05:26:14 nd02 kernel: [<c019d999>] sysfs_follow_link+0x41/0x59 Dec 22 05:26:14 nd02 kernel: [<c016ee2f>] generic_readlink+0x2a/0x85 Dec 22 05:26:14 nd02 kernel: [<c017fc72>] __mark_inode_dirty+0x52/0x1a8 Dec 22 05:26:14 nd02 kernel: [<c012332f>] current_fs_time+0x59/0x67 Dec 22 05:26:14 nd02 kernel: [<c0177e61>] update_atime+0x67/0x8c Dec 22 05:26:14 nd02 kernel: [<c01674b5>] sys_readlink+0x7e/0x82 Dec 22 05:26:14 nd02 kernel: [<c0103af3>] sysenter_past_esp+0x54/0x75 Dec 22 05:26:17 nd02 kernel: Unable to handle kernel paging requestBadness in kref_get at lib/kref.c:32 Dec 22 05:26:17 nd02 kernel: [<c01d9c6a>] kref_get+0x3f/0x41 Dec 22 05:26:17 nd02 kernel: [<c01d92e0>] kobject_get+0x17/0x1e Dec 22 05:26:17 nd02 kernel: [<c019d896>] sysfs_getlink+0x38/0xfa Dec 22 05:26:17 nd02 kernel: [<c019d999>] sysfs_follow_link+0x41/0x59 Dec 22 05:26:17 nd02 kernel: [<c016ee2f>] generic_readlink+0x2a/0x85 Dec 22 05:26:17 nd02 kernel: [<c012332f>] current_fs_time+0x59/0x67 Dec 22 05:26:17 nd02 kernel: [<c0177e61>] update_atime+0x67/0x8c Dec 22 05:26:17 nd02 kernel: [<c01674b5>] sys_readlink+0x7e/0x82 Dec 22 05:26:17 nd02 kernel: [<c0103af3>] sysenter_past_esp+0x54/0x75 Dec 22 05:26:17 nd02 kernel: at virtual address 00200200 Dec 22 05:26:17 nd02 kernel: printing eip: Dec 22 05:26:17 nd02 kernel: c02583a1 Dec 22 05:26:17 nd02 kernel: *pde = 37eb7001 Dec 22 05:26:17 nd02 kernel: Oops: 0002 [#1] Dec 22 05:26:17 nd02 kernel: SMP Dec 22 05:26:17 nd02 kernel: Modules linked in: dm_round_robin dm_multipath binfmt_misc dm_mirror dm_mod video thermal proces sor fan button battery ac uhci_hcd usbcore hw_random shpchp pci_hotplug e1000 qla2300 qla2xxx scsi_transport_fc sd_mod Dec 22 05:26:17 nd02 kernel: CPU: 1 Dec 22 05:26:17 nd02 kernel: EIP: 0060:[<c02583a1>] Not tainted VLI Dec 22 05:26:17 nd02 kernel: EFLAGS: 00010002 (2.6.14.2smp) Dec 22 05:26:17 nd02 kernel: EIP is at scsi_device_dev_release+0x3d/0x113 Dec 22 05:26:17 nd02 kernel: eax: 00100100 ebx: c2c03194 ecx: 00200200 edx: 00000286 Dec 22 05:26:17 nd02 kernel: esi: c2c03008 edi: c2c03000 ebp: c229d814 esp: d326fe68 Dec 22 05:26:17 nd02 kernel: ds: 007b es: 007b ss: 0068 Dec 22 05:26:17 nd02 kernel: Process udev (pid: 4108, threadinfo=d326e000 task=f6e3ca30) Dec 22 05:26:17 nd02 kernel: Stack: 7f7e7d7c c2c0320c c0371b08 c0371b20 c229d88c c01d935e c2c03194 c2c03224 Dec 22 05:26:17 nd02 kernel: c01d9362 c03754b8 c2c0320c c01d9c9e c2c0320c c019d854 c03754b8 ef1ac000 Dec 22 05:26:17 nd02 kernel: c0365040 00000000 c01d938a c2c03224 c01d9362 c019d927 c2c0320c c03754b8 Dec 22 05:26:17 nd02 kernel: Call Trace: Dec 22 05:26:17 nd02 kernel: [<c01d935e>] kobject_cleanup+0x77/0x7b Dec 22 05:26:17 nd02 kernel: [<c01d9362>] kobject_release+0x0/0xa Dec 22 05:26:17 nd02 kernel: [<c01d9c9e>] kref_put+0x32/0x84 Dec 22 05:26:17 nd02 kernel: [<c019d854>] sysfs_get_target_path+0x73/0x7d Dec 22 05:26:17 nd02 kernel: [<c01d938a>] kobject_put+0x1e/0x22 Dec 22 05:26:17 nd02 kernel: [<c01d9362>] kobject_release+0x0/0xa Dec 22 05:26:17 nd02 kernel: [<c019d927>] sysfs_getlink+0xc9/0xfa Dec 22 05:26:17 nd02 kernel: [<c019d999>] sysfs_follow_link+0x41/0x59 Dec 22 05:26:17 nd02 kernel: [<c016ee2f>] generic_readlink+0x2a/0x85 Dec 22 05:26:17 nd02 kernel: [<c017fc72>] __mark_inode_dirty+0x52/0x1a8 Dec 22 05:26:17 nd02 kernel: [<c012332f>] current_fs_time+0x59/0x67 Dec 22 05:26:17 nd02 kernel: [<c0177e61>] update_atime+0x67/0x8c Dec 22 05:26:17 nd02 kernel: [<c01674b5>] sys_readlink+0x7e/0x82 Dec 22 05:26:17 nd02 kernel: [<c0103af3>] sysenter_past_esp+0x54/0x75 Dec 22 05:26:17 nd02 kernel: Code: ff ff 8d bb 6c fe ff ff 8d 75 ec 8b 40 2c e8 cc df 0a 00 83 86 34 01 00 00 01 8d b3 74 fe ff ff 8b 4e 04 89 c2 8b 83 74 fe ff ff <89> 01 89 48 04 c7 46 04 00 02 20 00 8d b3 7c fe ff ff 8b 83 7c Dec 22 05:26:19 nd02 multipathd: sdc: path checker registered What can I do ? Thanks for any suggestion! Best regards! Luckey -- dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel