Loading snapshot with -loadvm?

Loading snapshot with -loadvm?

[Jun Koi]

hi,

i am using qemu-kvm 0.13.0. i created a snapshot (of my Win7-x64
image) like below:

qemu-img snapshot -c test img.win7

this created a snapshot named test on my image. then i tried to start
the snapshot VM, like below:

qemu-system-x86_64 -m 2000 -vga std -usb -usbdevice tablet -localtime
-loadvm 2 -hda img.qcow2.win7_x64

but then i have a problem: the Qemu window shows up, with "[Stopped]"
at window caption. it stays forever there, and doesnt proceed.

is this a bug, or did i do something wrong?

(i am on Ubuntu Linux 64bit, if that matters)

thanks,
Jun

Re: Loading snapshot with -loadvm?

[Stefan Hajnoczi]

On Fri, Nov 26, 2010 at 8:47 AM, Jun Koi <junkoi2004@gmail.com> wrote:
> this created a snapshot named test on my image. then i tried to start
> the snapshot VM, like below:
>
> qemu-system-x86_64 -m 2000 -vga std -usb -usbdevice tablet -localtime
> -loadvm 2 -hda img.qcow2.win7_x64
>
> but then i have a problem: the Qemu window shows up, with "[Stopped]"
> at window caption. it stays forever there, and doesnt proceed.
>
> is this a bug, or did i do something wrong?

Solution: Switch to the QEMU monitor (Ctrl+Alt+2) and type 'c' to
continue the VM.  To switch back to the VM's display use Ctrl+Alt+1.

I checked that it is expected behavior:
    if (loadvm) {
        if (load_vmstate(loadvm) < 0) {
            autostart = 0;
        }
    }

autostart = 0 means that your VM will be stopped.

I'm not sure why -loadvm implies the VM will be stopped, there's
already a different command-line option to keep the VM stopped (-S).

Stefan

Re: Loading snapshot with -loadvm?

[Jun Koi]

On Fri, Nov 26, 2010 at 5:18 PM, Stefan Hajnoczi <stefanha@gmail.com> wrote:
> On Fri, Nov 26, 2010 at 8:47 AM, Jun Koi <junkoi2004@gmail.com> wrote:
>> this created a snapshot named test on my image. then i tried to start
>> the snapshot VM, like below:
>>
>> qemu-system-x86_64 -m 2000 -vga std -usb -usbdevice tablet -localtime
>> -loadvm 2 -hda img.qcow2.win7_x64
>>
>> but then i have a problem: the Qemu window shows up, with "[Stopped]"
>> at window caption. it stays forever there, and doesnt proceed.
>>
>> is this a bug, or did i do something wrong?
>
> Solution: Switch to the QEMU monitor (Ctrl+Alt+2) and type 'c' to
> continue the VM.  To switch back to the VM's display use Ctrl+Alt+1.
>

yes, i tried that, but the problem is that the Qemu window is not
responsive. looks like it hangs up ...

i even tried with -monitor stdio, then at console type "c", but the
monitor is not responsive, either.

> I checked that it is expected behavior:
>    if (loadvm) {
>        if (load_vmstate(loadvm) < 0) {
>            autostart = 0;
>        }
>    }

>
> autostart = 0 means that your VM will be stopped.

but that happens when load_vmstate() < 0, which means something is wrong?

i must look at that code more closely.

thanks,
J

Re: Loading snapshot with -loadvm?

[Stefan Hajnoczi]

On Fri, Nov 26, 2010 at 9:26 AM, Jun Koi <junkoi2004@gmail.com> wrote:
> On Fri, Nov 26, 2010 at 5:18 PM, Stefan Hajnoczi <stefanha@gmail.com> wrote:
>> On Fri, Nov 26, 2010 at 8:47 AM, Jun Koi <junkoi2004@gmail.com> wrote:
>>> this created a snapshot named test on my image. then i tried to start
>>> the snapshot VM, like below:
>>>
>>> qemu-system-x86_64 -m 2000 -vga std -usb -usbdevice tablet -localtime
>>> -loadvm 2 -hda img.qcow2.win7_x64
>>>
>>> but then i have a problem: the Qemu window shows up, with "[Stopped]"
>>> at window caption. it stays forever there, and doesnt proceed.
>>>
>>> is this a bug, or did i do something wrong?
>>
>> Solution: Switch to the QEMU monitor (Ctrl+Alt+2) and type 'c' to
>> continue the VM.  To switch back to the VM's display use Ctrl+Alt+1.
>>
>
> yes, i tried that, but the problem is that the Qemu window is not
> responsive. looks like it hangs up ...
>
> i even tried with -monitor stdio, then at console type "c", but the
> monitor is not responsive, either.
>
>> I checked that it is expected behavior:
>>    if (loadvm) {
>>        if (load_vmstate(loadvm) < 0) {
>>            autostart = 0;
>>        }
>>    }
>
>>
>> autostart = 0 means that your VM will be stopped.
>
> but that happens when load_vmstate() < 0, which means something is wrong?
>
> i must look at that code more closely.

Me too, I missed the < 0.

Stefan