Re: [Qemu-devel] segfault while booting from saved snapshot

[Shehbaz Jaffer]

Hi,

Could anyone please give me the command to do live-migration to to a
file? I have tried searching on QEMU Wiki but all the articles that I
have come across point to snapshotting the disk, and not the entire VM
to a file.

Appreciate your help.

Thanks,
Shehbaz

On Sat, Apr 19, 2014 at 11:07 PM, Shehbaz Jaffer
<address@hidden> wrote:
> Thankyou for your reply. Live migration does seem like an interesting option
> to explore. I will look into it and get back if I get stuck.
>
>
> On Wed, Apr 16, 2014 at 6:16 PM, Kevin Wolf <address@hidden> wrote:
>>
>> Am 15.04.2014 um 16:55 hat Shehbaz Jaffer geschrieben:
>> > Thankyou for your reply. I do not face the error using qemu.1.7.1
>> > version.
>> >
>> > 1 quick question:
>> >
>> > I want to create a qcow2 image file after my VM has completed booting;
>> > i.e.,
>> > when I boot from this new snapshot, I should directly get to my VMs
>> > login
>> > prompt. How can i create such a qcow2 snapshot?
>> >
>> > I tried stopped the VM using QMP after the VM had completed booting, and
>> > then
>> > using host CLI to create a qcow2 image :
>> >
>> > qemu-img create -b ubuntu.qcow2 -f qcow2 newsnap.qcow2
>> >
>> > This created a new qcow2 file - newsnap.qcow2 on top of ubuntu.qcow2,
>> > however
>> > when I boot using newsnap.qcow2, It takes me again through the complete
>> > boot
>> > process - till the login prompt.
>> >
>> > Is there a way to create the qcow2 snapshot after VM has completed
>> > booting?
>>
>> The reason for this is that you only create a snapshot of the disk this
>> way, not of the VM state (i.e. RAM contents, device states, etc.)
>>
>> The most convenient way when you're using qemu directly is probably
>> using internal snapshots. This is what the savevm/loadvm HMP commands
>> provide (not sure if there is a QMP equivalent); you can also use the
>> -loadvm command line parameter to start a VM from a snapshot.
>>
>> Another option is that you take an external snapshot in a new qcow2 file
>> like you did, but you additionally do a live migration into a file. When
>> restarting the VM, you need to use the -incoming option and feed that
>> file back to qemu. As this is a bit more cumbersome, this is probably
>> more an option for management tools than for manual use.
>>
>> Kevin
>
>
>
>
> --
> Shehbaz Jaffer
> MTS | Advanced Technology Group |  NetApp



-- 
Shehbaz Jaffer
MTS | Advanced Technology Group |  NetApp