Hi folks, I'm trying to set up access to our SAN, 5 cabinets of 6320 storage, from CentOS 4.3 using dm-multipath and two Emulex lpfc cards. So far I can see the correct arrays through the zoning and have setup multipath.conf as below: defaults { user_friendly_names yes polling_interval 1 path_checker tur path_grouping_policy group_by_serial } devnode_blacklist { devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*" devnode "^hd[a-z]" devnode "^sd[a-b]" # sda and sdb are internal 3ware raid and sata system disk devnode "^cciss!c[0-9]d[0-9]*" } multipaths { multipath { wwid 360003baccb976000426f26d30004c45a alias cab2a01t0 } multipath { wwid 360003baccb976000426f27a00006ae93 alias cab2a01t1 } ... snip more multipath definitions.... } multipath -ll shows.. cab2a01t2 (360003baccb976000426f289000049adb) [size=1638 GB][features="0"][hwhandler="0"] \_ round-robin 0 [active] \_ 3:0:0:2 sde 8:64 [failed][faulty] \_ 4:0:0:2 sdj 8:144 [active][ready] cab2a01t1 (360003baccb976000426f27a00006ae93) [size=1638 GB][features="0"][hwhandler="0"] \_ round-robin 0 [active] \_ 3:0:0:1 sdd 8:48 [active][ready] \_ 4:0:0:1 sdi 8:128 [active][ready] cab2a01t0 (360003baccb976000426f26d30004c45a) [size=1638 GB][features="0"][hwhandler="0"] \_ round-robin 0 [active] \_ 3:0:0:0 sdc 8:32 [active][ready] \_ 4:0:0:0 sdh 8:112 [active][ready] but the error log is filling up with kernel: Device sde not ready. kernel: end_request: I/O error, dev sde, sector 2181037632 multipathd: 8:64: mark as failed multipathd: cab2a01t2: remaining active paths: 1 multipathd: 8:64: tur checker reports path is up multipathd: 8:64: reinstated multipathd: cab2a01t2: remaining active paths: 2 kernel: Device sde not ready. kernel: end_request: I/O error, dev sde, sector 3187670215 kernel: device-mapper: dm-multipath: Failing path 8:64. etc. I guess I should be using something other than the default for prio_callout, but what? Please can someone give me hints on the correct incantation for path_checker, path_grouping_policy, prio_callout Many thanks Andrew -- dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel