Hello, I have a test server connected to an IBM DS6800 storage. It is a blade bl480c with two qlogic hbas, connected to 2 fc-switches. RH EL 4.6 x86_64 installed (kernel 2.6.9-67.ELsmp) device-mapper-1.02.21-1.el4 device-mapper-multipath-0.4.5-27.RHEL4 In boot messages I have for the hbas: qla2400 0000:0c:00.0: Found an ISP2432, irq 185, iobase 0xffffff000001c000 QLogic Fibre Channel HBA Driver: 8.01.07-d4 QLogic QMH2462 - SBUS to 2Gb FC, Dual Channel ISP2432: PCIe (2.5Gb/s x4) @ 0000:0c:00.0 hdma+, host#=0, fw=4.00.150 [IP] Vendor: IBM Model: 1750500 Rev: .155 Type: Direct-Access ANSI SCSI revision: 05 On the storage I have access to two luns, so that in total I get 8 paths and disks from sda to sdh. In multipath I'm using default os install config for ds6800 (storage 1750500) so it should be: # device { # vendor "IBM" # product "1750500" # path_grouping_policy group_by_prio # getuid_callout "/sbin/scsi_id -g -u -s" # prio_callout "/sbin/mpath_prio_alua %d" # features "1 queue_if_no_path" # path_checker tur # } In normal operation the command "multipath -ll" gives: [root@test-rhel-p ~]# multipath -ll mpath1 (3600507630efe05800000000000001700) [size=20 GB][features="1 queue_if_no_path"][hwhandler="0"] \_ round-robin 0 [prio=100][active] \_ 0:0:1:1 sdd 8:48 [active][ready] \_ 1:0:1:1 sdh 8:112 [active][ready] \_ round-robin 0 [prio=20][enabled] \_ 0:0:0:1 sdb 8:16 [active][ready] \_ 1:0:0:1 sdf 8:80 [active][ready] mpath0 (3600507630efe05800000000000001600) [size=20 GB][features="1 queue_if_no_path"][hwhandler="0"] \_ round-robin 0 [prio=100][active] \_ 0:0:0:0 sda 8:0 [active][ready] \_ 1:0:0:0 sde 8:64 [active][ready] \_ round-robin 0 [prio=20][enabled] \_ 0:0:1:0 sdc 8:32 [active][ready] \_ 1:0:1:0 sdg 8:96 [active][ready] We had a code update for the storage, and so I wanted to test the multipath behaviour. It was made in concurrent mode. I get a first path-change whithout problems, probably when fisrt controller was updated. mpath1: \_ round-robin 0 [enabled] \_ 0:0:0:1 sdb 8:16 [failed] \_ 1:0:0:1 sdf 8:80 [failed] and mpath0: \_ round-robin 0 [enabled] \_ 0:0:0:0 sda 8:0 [failed] \_ 1:0:0:0 sde 8:64 [failed] while the other two path group remained active. At the end of upgrade, probably with the second controller update, I get the situation below. while other servers with windows and Linux (using sdd) came back with all paths, this server retains two paths in failed state: [root@test-rhel-p RPMS]# multipath -l mpath1 (3600507630efe05800000000000001700) [size=20 GB][features="1 queue_if_no_path"][hwhandler="0"] \_ round-robin 0 [enabled] \_ 0:0:1:1 sdd 8:48 [failed][faulty] \_ 1:0:1:1 sdh 8:112 [active] \_ round-robin 0 [enabled] \_ 0:0:0:1 sdb 8:16 [active] \_ 1:0:0:1 sdf 8:80 [active] mpath0 (3600507630efe05800000000000001600) [size=20 GB][features="1 queue_if_no_path"][hwhandler="0"] \_ round-robin 0 [active] \_ 0:0:0:0 sda 8:0 [active] \_ 1:0:0:0 sde 8:64 [active] \_ round-robin 0 [enabled] \_ 0:0:1:0 sdc 8:32 [failed][faulty] \_ 1:0:1:0 sdg 8:96 [active] with messages every 5 seconds of type: error calling out /sbin/mpath_prio_alua /dev/sdc error calling out /sbin/mpath_prio_alua /dev/sdd Other information: [root@test-rhel-p ]# sg_inq /dev/sdc sg_inq: error opening file: /dev/sdc: No such device or address [root@test-rhel-p RPMS]# ll /dev/sdc brw-rw---- 1 root disk 8, 32 Jun 11 19:03 /dev/sdc [root@test-rhel-p RPMS]# sg_inq /dev/sda standard INQUIRY: PQual=0 Device_type=0 RMB=0 version=0x05 [SPC-3] [AERC=0] [TrmTsk=0] NormACA=1 HiSUP=1 Resp_data_format=2 SCCS=0 ACC=0 TGPS=1 3PC=0 Protect=0 BQue=0 EncServ=0 MultiP=1 (VS=0) [MChngr=0] [ACKREQQ=0] Addr16=0 [RelAdr=0] WBus16=0 Sync=0 Linked=0 [TranDis=0] CmdQue=1 Clocking=0x0 QAS=0 IUS=0 length=164 (0xa4) Peripheral device type: disk Vendor identification: IBM Product identification: 1750500 Product revision level: .441 Unit serial number: 68778501600 Any help to get up the paths? Could it help a scsi rescan? What should be the correct command in this case? The system is operational and without interruption on disk acces for the users, but I don't understand why the paths don't come up again... Thanks in advance for help or suggestions. Gianluca