switching from active to failed.

switching from active to failed.

[egroegnibus]

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Hi, I had a question on how a target can force a path on Linux to go to "failed" state. 

In the multipath -l output below, there are 4 paths to a device and all the paths are "active". What kind of response/sense code is required so as to make path sddd below to go from active to failed state ?

I guess another question is : how does device mapper recognize that a path is active or failed, in other words what sequence of SCSI opcodes is sent by Linux to discover a path and mark it dead/failed or alive ?


mpath153 (360060480000190102221533031303030) dm-154 EMC,SYMMETRIX
[size=938M][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=0][active]
\_ 3:0:0:11  sddd 70:176  [active][undef]
\_ 4:0:0:11  sdgt 132:144 [active][undef]
\_ 5:0:0:182 sdka 65:480  [active][undef]
\_ 6:0:0:182 sdln 68:336  [active][undef]


Thanks

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