[libvirt] Question about fsfreeze/fsthaw API

[Michal Privoznik]

On 07.11.2013 01:31, Tomoki Sekiyama wrote:
> Hi all,
> 
> Is there any plans to add APIs to execute fsfreeze/fsthaw in qemu guests?
> (something like virDomainFSFreeze(domain,timeout,flags) and
>                 virDomainFSThaw(domain,timeout,flags))
> 
> These would be useful in the case a guest has a disk device with its own
> snapshot feature, such as cinder volumes in OpenStack configuration.
> In such cases, libvirt clients want to issue fsfreeze/fsthaw before/after
> taking the disk snapshot.
> 
> Currently we can execute them using virDomainQemuAgentCommand(). (e.g.
> virsh qemu-agent-command dom '{"execute":"guest-fsfreeze-freeze"}' )
> 
> However, this is exposing internal implementation too much. And it
> cannot leverage future implementation for the other hypervisors.
> So it would be nice if we have well-defined API for fsfreeze/fsthaw.
> 
> If there is no plan for these API and this is acceptable, I will try to
> implement this.
> Any comments are welcome.
> 
> Thanks,
> Tomoki Sekiyama
> 

I am not aware of somebody wanting these APIs exposed hence I don't know
if somebody is working on it. But since there is a clear usage scenario
I'd say go for it.

Michal