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From: Michael Reed <mdr@sgi.com>
To: Mike Christie <michaelc@cs.wisc.edu>
Cc: James.Smart@Emulex.Com, Jeremy Higdon <jeremy@sgi.com>,
	Gary Hagensen <gwh@sgi.com>,
	linux-scsi <linux-scsi@vger.kernel.org>, Jim Nead <jnead@sgi.com>,
	James Bottomley <James.Bottomley@SteelEye.com>
Subject: Re: fc transport creates second set of targets for devices in an "md"
Date: Fri, 09 Jun 2006 11:35:24 -0500	[thread overview]
Message-ID: <4489A34C.8040007@sgi.com> (raw)
In-Reply-To: <4488864E.2000009@cs.wisc.edu>



Mike Christie wrote:
> 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.
> 

So, how about a callback to the driver, md, with the reference so that it
can release said reference?

Mike

  reply	other threads:[~2006-06-09 16:35 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-06-08 19:13 fc transport creates second set of targets for devices in an "md" Michael Reed
2006-06-08 19:57 ` James Smart
2006-06-09 16:26   ` Michael Reed
2006-06-09 18:10     ` Michael Reed
2006-06-09 18:22       ` Michael Reed
2006-06-08 20:19 ` Mike Christie
2006-06-09 16:35   ` Michael Reed [this message]
2006-06-09 19:34     ` Mike Christie
2006-06-09 19:52     ` James Smart
2006-06-09  0:43 ` James Bottomley
2006-06-09 16:35   ` Michael Reed
2006-06-09 19:23     ` James Bottomley

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