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From: Max Reitz <mreitz@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	qemu-devel <qemu-devel@nongnu.org>
Cc: Kevin Wolf <kwolf@redhat.com>, Eric Blake <eblake@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	"Denis V. Lunev" <den@openvz.org>,
	Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Subject: Re: [Qemu-devel] export root node for write through NBD
Date: Thu, 30 Nov 2017 15:21:47 +0100	[thread overview]
Message-ID: <76f5ec24-112f-455a-4ad4-5c97d7182f36@redhat.com> (raw)
In-Reply-To: <3c1d9325-56a9-225d-4ff8-230f8ed52fed@virtuozzo.com>

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On 2017-11-30 08:47, Vladimir Sementsov-Ogievskiy wrote:
> Hi all.
> 
> We need the following option: start vm in stopped mode (-S) and write
> it's disk before start through NBD.
> It should be absolutely safe, but unfortunately it is disallowed by root
> role of the disk.
> Is there any workaround or if not, what is a true way to implement this
> possibility?
> 
> ----
> error message:
>     unable to execute QEMU command 'nbd-server-add': Conflicts with use
> by drive0 as 'root', which does not allow 'write' on #block100
> 
> -- 

One thing that comes to mind is adding the guest device only after you
are done with NBD.

The other of course is to set share-rw=on for the device.

Max


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  reply	other threads:[~2017-11-30 14:21 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-30  7:47 [Qemu-devel] export root node for write through NBD Vladimir Sementsov-Ogievskiy
2017-11-30 14:21 ` Max Reitz [this message]
2017-11-30 14:33   ` Kevin Wolf
2017-12-15 16:13     ` Vladimir Sementsov-Ogievskiy

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