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From: Markus Armbruster <armbru@redhat.com>
Subject: Re: [Qemu-devel] Re: [PATCH 08/12] block: Catch attempt to attach
	multiple devices to a blockdev
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	<20100626101146.GC27699@lst.de> <m3eiftsvk4.fsf@blackfin.pond.sub.org>
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Date: Wed, 30 Jun 2010 13:33:12 +0200
In-Reply-To: <20100627093609.GA12016@lst.de> (Christoph Hellwig's message of
	"Sun, 27 Jun 2010 11:36:09 +0200")
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To: Christoph Hellwig <hch@lst.de>
Cc: kwolf@redhat.com, qemu-devel@nongnu.org, kraxel@redhat.com

Christoph Hellwig <hch@lst.de> writes:

>Markus Armbruster <armbru@redhat.com> writes:
>
>> Christoph Hellwig <hch@lst.de> writes:
>>
>>> On Fri, Jun 25, 2010 at 06:53:28PM +0200, Markus Armbruster wrote:
>>>> For instance, -device scsi-disk,drive=foo -device scsi-disk,drive=foo
>>>> happily creates two SCSI disks connected to the same block device.
>>>> It's all downhill from there.
>>>
>>> And from some quick testing a while ago the thing seems to actually
>>> work.  Not that I think that it is a good idea, but do we want to change
>>> behaviour in that respect?
>>
>> Valid question.  I'd answer yes.  It's an easy error to make, and likely
>> to end in massive file system corruption in the guest.
>
> I suspect a modern distro in the guest will detect it as a multi-path setup.

Really?  The guest sees two disks, different serial numbers, possibly on
different buses (one could be SCSI, the other iDE).

[...]