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Date: Thu, 21 Jan 2016 14:55:27 +0300
From: Alexey <alukardd@alukardd.org>
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Message-ID: <814fa6064b6de361070d5e65b8a4010f@alukardd.org>
Subject: Re: [Qemu-devel] live migration between different qemu versions
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To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Qemu devel <qemu-devel@nongnu.org>

Hello.

On 2016-01-21 14:49, Dr. David Alan Gilbert wrote:
> * Alexey (alukardd@alukardd.org) wrote:
>> Hello,
>> 
>> On 2016-01-16 02:24, Eric Blake wrote:
>> >On 01/12/2016 05:11 AM, Dr. David Alan Gilbert wrote:
>> >
>> >>>Tell me please right way to append zeros to "BIOS (ia32) ROM Ext.
>> >>>(137*512)"
>> >>>file?
>> >>
>> >>I'd use dd; something like:
>> >>  dd if=/dev/zero bs=1 count=18944 >> theromfile
>> >>I think that should do it (203264-184320=18944)
>> >
>> >Or simpler:
>> >
>> >truncate --size=203264 theromfile
>> It's great! I have successfully did migration of VM from qemu 2.3.0 to 
>> qemu
>> 2.5.0.
>> 
>> But when I try migrate to another side I got error:
>> qemu-system-x86_64: error while loading state for instance 0x0 of 
>> device
>> 'fw_cfg'
>> qemu-system-x86_64: load of migration failed: No such file or 
>> directory
>> 
>> Is it possible to do this migration?
> 
> Backwards migration doens't get much upstream testing;  it looks like
> this is the same as:
> 
> https://bugs.launchpad.net/qemu/+bug/1536487
I saw it, thanks.

> 
> Dave
> 
>> Regards,
>> Alexey Mochkin.
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Regards,
Alexey Mochkin