[dm-devel] dm-multipath failover

[christophe varoqui]

The daemon should log in daemon.log
You can push the debug level to the max and post the trace.

In the mean time, you can also make sure you didn't apply the patchset
from Mike Christie which used to be appended a the tail of the -udm
patchset. These patches broke the event model used by the daemon.

regards,
cvaroqui

Le mercredi 24 novembre 2004 à 17:10 -0500, Jims a écrit :
> We have a Dell unit with 2 QLogic 23XX series cards which are providing
> multipathing to 3 EMC volumes. We're looking to have a failover setup (with
> /dev/sdc and /dev/sdf) so that if one of FC connects is pulled, multipathd
> will reroute the path to the other card and also be able to reestablish the
> connection when the Fiber is put back.
> 
> dmsetup is able to create the device in /udev (/udev/big01) and we're able to
> mount it. When I pull an FC cable, the mount does indeed failover, however
> when we put it back in and pull the other, we get a bunch of scsi errors and
> the mount gets remounted in read-only mode. How can we remedy this? Any
> similar experiences and/or suggestions? Thanks.
> 
> By the way, sda and sdb are the system drives. sdd,sde,sdg,sdh are other FC
> drives that we're not working with right now.
> 
> our DMsetup table is as follows:
> 
> DMsetup table <<start>>
> 0 1885645370 multipath 2 round-robin 1 0 /dev/sdc round-robin 1 0 /dev/sdf
> DMsetup table <<end>>
> 
> here is our multipath.conf:
> 
> multipath.conf <<start>>
> defaults {
>         multipath_tool  "/sbin/multipath -v 0 -S"
>         udev_dir        /udev
>         polling_interval 5
>         default_selector        round-robin
>         default_selector_args   0
>         default_path_grouping_policy    failover
>         default_getuid_callout  "/sbin/scsi_id -g -u -s"
>         default_prio_callout    "/bin/false"
> }
> 
> devnode_blacklist {
>         devnode cciss
>         devnode fd
>         devnode hd
>         devnode md
>         devnode dm
>         devnode sr
>         devnode scd
>         devnode st
>         devnode ram
>         devnode raw
>         devnode loop
>         devnode sda
>         devnode sdb
> }
> multipaths {
>         multipath {
>                 wwid    501566091000
>                 alias   big01
>                 path_grouping_policy    failover
>                 path_selector           round-robin
>         }
> }
> devices {
>         device {
>                 vendor                  "SEMC     "
>                 product                 "SYMMETRIX      "
>                 path_grouping_policy    failover
>                 getuid_callout          "/sbin/scsi_id -g -u -s"
>                 path_checker            readsector0
>                 path_selector           round-robin
>         }
> }
> multipath.conf <<end>>
> 
> and finally output of multipath -v2
> 
> output <<start>>
> #
> # all paths :
> #
> SEMC_____SYMMETRIX______501566091000 (1 0 0 1) sdc [ready ] (8:32) [SYMMETRIX
> ]
> SEMC_____SYMMETRIX______5015660D1000 (1 0 0 2) sdd [ready ] (8:48) [SYMMETRIX
> ]
> SEMC_____SYMMETRIX______501566111000 (1 0 0 3) sde [ready ] (8:64) [SYMMETRIX
> ]
> SEMC_____SYMMETRIX______501566091000 (2 0 0 1) sdf [ready ] (8:80) [SYMMETRIX
> ]
> SEMC_____SYMMETRIX______5015660D1000 (2 0 0 2) sdg [ready ] (8:96) [SYMMETRIX
> ]
> SEMC_____SYMMETRIX______501566111000 (2 0 0 3) sdh [ready ] (8:112) [SYMMETRIX
> ]
> #
> # all multipaths :
> #
> SEMC_____SYMMETRIX______501566091000 [SYMMETRIX       ]
>  \_(1 0 0 1) sdc [ready ] (8:32)
>  \_(2 0 0 1) sdf [ready ] (8:80)
> SEMC_____SYMMETRIX______5015660D1000 [SYMMETRIX       ]
>  \_(1 0 0 2) sdd [ready ] (8:48)
>  \_(2 0 0 2) sdg [ready ] (8:96)
> SEMC_____SYMMETRIX______501566111000 [SYMMETRIX       ]
>  \_(1 0 0 3) sde [ready ] (8:64)
>  \_(2 0 0 3) sdh [ready ] (8:112)
> #
> # device maps :
> #
> create:SEMC_____SYMMETRIX______501566091000:0 1885655040 multipath 2
> round-robin 1 0 8:80 round-robin 1 0 8:32
> create:SEMC_____SYMMETRIX______5015660D1000:0 1885655040 multipath 2
> round-robin 1 0 8:96 round-robin 1 0 8:48
> create:SEMC_____SYMMETRIX______501566111000:0 1885655040 multipath 2
> round-robin 1 0 8:112 round-robin 1 0 8:64
> output <<end>>
> 
> Help please.
> 
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-- 
christophe varoqui <christophe.varoqui at free.fr>