Hi, I have some problem with multipath-tools, multipath -ll web (3600601608c9012006269b8f63b87d911) [size=5 GB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [prio=1][enabled] \_ 1:0:0:4 sdf 8:80 [active][ready] mysql (3600601608c901200ccfe543f4053d911) [size=200 GB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [enabled] \_ 1:0:0:1 sdc 8:32 [active][ready] mail (3600601608c9012008ae5de2cc985d911) [size=300 GB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [prio=1][enabled] \_ 1:0:0:0 sdb 8:16 [active][ready] 3600601608c901200a8b8972f4053d911 [size=100 MB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [prio=1][enabled] \_ 1:0:0:2 sdd 8:48 [active][ready] 3600601608c901200bc7680294053d911 [size=100 MB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [enabled] \_ 1:0:0:3 sde 8:64 [active][ready] only one disk is active, I have to do the command: nodob mapper # multipath /dev/sdb error calling out /sbin/scsi_id -g -u -s /block/sda reload: mail (3600601608c9012008ae5de2cc985d911) [size=300 GB][features="1 queue_if_no_path"][hwhandler="1 emc"] \_ round-robin 0 [prio=1] \_ 1:0:0:0 sdb 8:16 [active][ready] \_ 2:0:0:0 sdg 8:96 [ready] and now the other path is activated: nodob mapper # multipath /dev/sdb error calling out /sbin/scsi_id -g -u -s /block/sda reload: mail (3600601608c9012008ae5de2cc985d911) [size=300 GB][features="1 queue_if_no_path"][hwhandler="1 emc"] \_ round-robin 0 [prio=1] \_ 1:0:0:0 sdb 8:16 [active][ready] \_ 2:0:0:0 sdg 8:96 [active][ready] multipath -ll web (3600601608c9012006269b8f63b87d911) [size=5 GB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [prio=1][enabled] \_ 1:0:0:4 sdf 8:80 [active][ready] mysql (3600601608c901200ccfe543f4053d911) [size=200 GB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [enabled] \_ 1:0:0:1 sdc 8:32 [active][ready] mail (3600601608c9012008ae5de2cc985d911) [size=300 GB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [prio=1][enabled] \_ 1:0:0:0 sdb 8:16 [active][ready] \_ 2:0:0:0 sdg 8:96 [active][ready] 3600601608c901200a8b8972f4053d911 [size=100 MB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [prio=1][enabled] \_ 1:0:0:2 sdd 8:48 [active][ready] 3600601608c901200bc7680294053d911 [size=100 MB][features="0"][hwhandler="1 emc"] \_ round-robin 0 [enabled] \_ 1:0:0:3 sde 8:64 [active][ready] in /dev/mapper I have the following: brw------- 1 root root 254, 3 Sep 12 2005 3600601608c901200a8b8972f4053d911 brw------- 1 root root 254, 1 Sep 12 2005 3600601608c901200bc7680294053d911 crw-rw---- 1 root root 10, 63 Sep 12 2005 control brw------- 1 root root 254, 4 Sep 12 2005 mail brw------- 1 root root 254, 5 Sep 12 2005 mail1 brw------- 1 root root 254, 0 Sep 10 20:23 mysql brw------- 1 root root 254, 2 Sep 10 20:23 mysql1 brw------- 1 root root 254, 7 Sep 12 2005 vg00-admin brw------- 1 root root 254, 13 Sep 12 2005 vg00-log brw------- 1 root root 254, 11 Sep 12 2005 vg00-portage brw------- 1 root root 254, 8 Sep 12 2005 vg00-root brw------- 1 root root 254, 9 Sep 12 2005 vg00-tmp brw------- 1 root root 254, 10 Sep 12 2005 vg00-usr brw------- 1 root root 254, 12 Sep 12 2005 vg00-var brw------- 1 root root 254, 6 Sep 12 2005 web is correct? grep -v "#" /etc/multipath.conf defaults { multipath_tool "/sbin/multipath -v0" udev_dir /dev } multipaths { multipath { wwid 3600601608c9012008ae5de2cc985d911 alias mail path_grouping_policy multibus path_checker readsector0 path_selector "round-robin 0" failback immediate } multipath { wwid 3600601608c901200ccfe543f4053d911 alias mysql path_grouping_policy multibus path_checker readsector0 path_selector "round-robin 0" } multipath { wwid 3600601608c9012006269b8f63b87d911 alias web path_grouping_policy multibus path_checker readsector0 path_selector "round-robin 0" } } nodob mapper # lspci 0000:00:00.0 Host bridge: Intel Corp. E7520 Memory Controller Hub (rev 09) 0000:00:02.0 PCI bridge: Intel Corp. E7525/E7520/E7320 PCI Express Port A (rev 09) 0000:00:04.0 PCI bridge: Intel Corp. E7525/E7520 PCI Express Port B (rev 09) 0000:00:05.0 PCI bridge: Intel Corp. E7520 PCI Express Port B1 (rev 09) 0000:00:06.0 PCI bridge: Intel Corp. E7520 PCI Express Port C (rev 09) 0000:00:1d.0 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #1 (rev 02) 0000:00:1d.1 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #2 (rev 02) 0000:00:1d.2 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #3 (rev 02) 0000:00:1d.7 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller (rev 02) 0000:00:1e.0 PCI bridge: Intel Corp. 82801 PCI Bridge (rev c2) 0000:00:1f.0 ISA bridge: Intel Corp. 82801EB/ER (ICH5/ICH5R) LPC Interface Bridge (rev 02) 0000:00:1f.1 IDE interface: Intel Corp. 82801EB/ER (ICH5/ICH5R) IDE Controller (rev 02) 0000:01:00.0 PCI bridge: Intel Corp. 80332 [Dobson] I/O processor (rev 06) 0000:01:00.2 PCI bridge: Intel Corp. 80332 [Dobson] I/O processor (rev 06) 0000:02:0e.0 RAID bus controller: Dell PowerEdge Expandable RAID controller 4 (rev 06) 0000:05:00.0 PCI bridge: Intel Corp. 6700PXH PCI Express-to-PCI Bridge A (rev 09) 0000:05:00.2 PCI bridge: Intel Corp. 6700PXH PCI Express-to-PCI Bridge B (rev 09) 0000:06:07.0 Ethernet controller: Intel Corp. 82541GI/PI Gigabit Ethernet Controller (rev 05) 0000:07:08.0 Ethernet controller: Intel Corp. 82541GI/PI Gigabit Ethernet Controller (rev 05) 0000:08:00.0 PCI bridge: Intel Corp. 6700PXH PCI Express-to-PCI Bridge A (rev 09) 0000:08:00.2 PCI bridge: Intel Corp. 6700PXH PCI Express-to-PCI Bridge B (rev 09) 0000:09:04.0 SCSI storage controller: Adaptec AHA-3960D / AIC-7899A U160/m (rev 01) 0000:09:04.1 SCSI storage controller: Adaptec AHA-3960D / AIC-7899A U160/m (rev 01) 0000:0a:02.0 Fibre Channel: QLogic Corp. QLA2312 Fibre Channel Adapter (rev 02) 0000:0a:03.0 Fibre Channel: QLogic Corp. QLA2312 Fibre Channel Adapter (rev 02) 0000:0b:0d.0 VGA compatible controller: ATI Technologies Inc Radeon RV100 QY [Radeon 7000/VE] nodob mapper # lsmod Module Size Used by dm_round_robin 4096 1 qla2300 125056 0 qla2xxx 112092 20 qla2300 firmware_class 8832 1 qla2xxx dm_emc 6144 1 dm_multipath 19464 3 dm_round_robin,dm_emc dm_mod 52380 12 dm_multipath from dmesg: device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) e1000: eth0: e1000_watchdog_task: NIC Link is Up 1000 Mbps Full Duplex e1000: eth1: e1000_watchdog_task: NIC Link is Up 1000 Mbps Full Duplex device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: emc_pg_init: sending switch-over command device-mapper: dm-emc: emc_pg_init: sending switch-over command device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) I'm using gentoo, udev-0.68, device-mapper-1.03, multipath-tools-0.4.5, kernel-2.6.13 (2.6.12 give oops when load qla2300) some suggestions? I have to post other specific configuration o log file? thanks, Nicola