Re: [Qemu-devel] virsh dump (qemu guest memory dump?): KASLR enabled linux guest support

[Paolo Bonzini]

On 09/11/2016 17:01, Daniel P. Berrange wrote:
> On Wed, Nov 09, 2016 at 04:38:36PM +0100, Laszlo Ersek wrote:
>> On 11/09/16 15:47, Daniel P. Berrange wrote:
>>>>> That doesn't help with trying to diagnose a crash during boot up, since
>>>>> the guest agent isn't running till fairly late. I'm also concerned that
>>>>> the QEMU guest agent is likely to be far from widely deployed in guests,
>>
>> I have no hard data, but from the recent Fedora and RHEL-7 guest
>> installations I've done, it seems like qga is installed automatically.
>> (Not sure if that's because Anaconda realizes it's installing the OS in
>> a VM.) Once I made sure there was an appropriate virtio-serial config in
>> the domain XMLs, I could talk to the agents (mainly for fstrim's sake)
>> immediately.
> 
> I'm thinking about cloud deployment where people rarely use Anaconda
> directly - they'll use a pre-built cloud image, or customize the basic
> cloud image. Neither Fedora or Ubuntu include the qemu guest agent in
> their cloud images AFAICT, so very few OpenStack deployments will have
> QEMU guest agent in at this time.

That's a bug in my opinion.  The guest agent is necessary in order to
avoid losing data in snapshots.  We should not only get distros to embed
the guest agent, but also to include the relevant freeze/thaw hooks.

Paolo

> Of course we could try to get distros to embed qemu guets agent by
> default, but its not clear if we'd succeed, given how aggressive
> they are at stripping stuff out to create the smallest practical
> images.
> 
> Regards,
> Daniel
>