Re: fc transport creates second set of targets for devices in an "md"

[Mike Christie <michaelc@cs.wisc.edu>]

Michael Reed wrote:
> I created an md device on two fibre channel disks, sde and sdf.
> I then disabled the switch port to which the hba is connected.
> After the remote port time out messages, I re-enabled the switch
> port.  Three things happen that are weird.  First, two unexpected
> responses while scanning.  Second, the creation of sdm and
> sdn.  Third, the md device remains inaccessible.
> 
> I don't think this is working the way it's intended to.  I
> suspect it will cause big problems for multi-path volume managers
> in a fail back situation.
> 

Even if the rport is removed and the devices under it are removed, md
can still have a reference to the device so the memory does not
disappear on it (MD still thinks the device is there but scsi says it is
gone basically). Because of this, when you plug in the cable again and a
new rport is created sd.c can end up allocating another sdX value.