Re: [Qemu-devel] SIGTERM signal to qemu-kvm process

[Jatin Davey <jashokda@cisco.com>]

On 4/8/2015 9:06 PM, Kevin Wolf wrote:
> Am 08.04.2015 um 07:07 hat Jatin Davey geschrieben:
>> I am using QEMU 0.12.1 as the hypervisor in my RHEL installation of 6.5.
>>
>> I wanted to know if there are any side-effects with respect to VM image
>> corruption when i use SIGTERM signal to kill a qemu-kvm process which
>> effectively stops my VM running on the host.
>>
>> Appreciate if you can provide me some valuable information in this regard.
> Sending SIGTERM is equivalent to sending a 'quit' monitor command. This
> is a clean shutdown as far as qemu is concerned, but of course it isn't
> for your guest OS.
>
> If your guest behaves correctly, you may lose data that wasn't flushed
> to disk yet, but you should not get any corruption. The image file
> structure itself (i.e. what 'qemu-img check' checks) should be fully
> consistent.
>
> Sending SIGKILL is a bit worse (just like a host crash/power failure),
> because then even the image file may be inconsistent. But again, if the
> guest behaves correct (and assuming there are no qemu bugs and you're
> not using cache=unsafe), even in this case the result should never be
> corruption, but only loss of data that wasn't flushed to disk yet.
>
> Kevin
Thanks Kevin.

Appreciate your prompt response in this regard.

Thanks
Jatin