qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Problems about "live backup vm" patch, which is issued


From: Wenchao Xia
Subject: Re: [Qemu-devel] Problems about "live backup vm" patch, which is issued by Wenchao Xia.
Date: Wed, 27 Feb 2013 10:19:20 +0800
User-agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130107 Thunderbird/17.0.2

Hi, Liu Ji
  It is embrassing to say that I forgot the version number too, consider
the date of that patch, it should be some version around qemu-1.3, I
remember that migration is not a stand alone thread at that time.

  I tested it with (TCG qemu)+(SDL)+(qcow2 image)+"ubuntu guest OS",
it seems fine. Spice is not tested, I guess most probably it is a
multi thread bug I have missed.

> Hi, Wenchao
> 
> In order to determine whether my test method or my system environment have
> problems,
> I want to test the patch on the qemu version which you used.
> You can give me a rough version number.
> 
> You told me that patch is based on the version before qemu-1.3. But in your
> patch,
> there is a diff:
>      --- a/savevm.c
>      +++ b/savevm.c
>      @@ -698,7 +698,7 @@ int qemu_get_byte(QEMUFile *f)
>           return result;
>       }
> 
>      -static int64_t qemu_ftell(QEMUFile *f)
>      +int64_t qemu_ftell(QEMUFile *f)
>       {
>           return f->buf_offset - f->buf_size + f->buf_index;
>       }
>      @@ -2061,32 +2061,10 @@ out:
>           return ret;
>       }
> But before qemu-1.3, the "qemu_ftell" function is not a static function.
> In qemu-1.3 and the following version, the "qemu_ftell" function is change
> to a static function. So I'm not sure which version you used.
> 
> 
> Which tool you used to connect the VM, Spice, VNC or others?
> When I use the Spice, after I "loadvm" the snapshot which is create by
> the "migrate image:" command, the qemu-kvm will be error or crash.
> But when I use VNC, it is OK.
> How do you think this issue? Please give me some suggestion.
> 
> And can you give me the detailed "qemu-kvm" command, which you used to
> start the VM.
> I want compare your "qemu-kvm" command and my.
> 
> 
> Best Regards
> 
> Liu Ji
> 
> 
> -----------------------------------------------------
> 
> 2013/2/19 Wenchao Xia <address@hidden>
> 
>> Hi, Liu Ji
>>    Thanks for trying my trival patch. That patch is based on the version
>> before qemu-1.3, and since qemu have important change about migration
>> from Juan after that, So I think it would not work since 1.3.
>>
>>    I am trying to fix the size problem now, and then reimplement a formal
>> patch of "live savevm" after that, as part of the incremental backup
>> enhancement, you can take a look of the plan at:
>> http://wiki.qemu.org/Features/VMSnapshotEnchancement
>>    Pls forgive me about the latency of the work, I have just come back
>> from vacation.:)
>>
>>> Hello Wenchao Xia,
>>> I am very interested in your "live backup vm" patch of qemu, which have
>>> been sent to qemu-devel mail-list in "8 Dec 2012".
>>> http://lists.gnu.org/archive/html/qemu-devel/2012-12/msg00800.html
>>>
>>> I have test your patch in qemu-1.3.1, but I have two problems:
>>>
>>> 1) After I exec the "migrate image:" command, although the CPU of VM is
>> not
>>> suspended, the running of VM is very slow. It is very difficult to
>> operate
>>> the VM
>>>
>>> by Spice.
>>> 2) When I "loadvm" the snapshot which is create by the "migrate image:"
>>> command, the Qemu output error. I change the version of qemu to 1.3.0,
>> the
>>> "loadvm"
>>>
>>> caused a crash.
>>> Could you tell me which baseline version of qemu you used? And do you
>> have
>>> the same problems?
>>> Do you have optimized the patch, and can you provide the latest patch for
>>> me?
>>>
>>> Thanks.
>>>
>>
>>
>> --
>> Best Regards
>>
>> Wenchao Xia
>>
>>
> 


-- 
Best Regards

Wenchao Xia




reply via email to

[Prev in Thread] Current Thread [Next in Thread]