Open Stack

On 1/22/2019 12:45 PM, Sean McGinnis wrote:
> On Tue, Jan 22, 2019 at 07:04:05PM +0100, Ignazio Cassano wrote:
>> Hi All,
>> Please,  I' d like to know if cinder backup  and/or  cinder snapshot call
>> qemu guest agent for fsfreezing.
>> If Yes, does it freeze file systems in the volume?
>> Regards
>> Ignazio
> Unfortunately no, initiating a snapshot or backup from Cinder does not call out
> to Nova to do any guest quiescing. There would need to be something else
> coordinating the calls between the guest OS and initiating the Cinder snapshot
> to do that.
> 
> Sean
> 

If you snapshot a volume-backed server in nova the compute API will 
attempt to quiesce the guest before creating the snapshot of the volume:

https://github.com/openstack/nova/blob/31956108e6e785407bdcc31dbc8ba99e6a28c96d/nova/compute/api.py#L3100

As for backups, the compute createBackup API does not support 
volume-backed servers:

https://github.com/openstack/nova/blob/31956108e6e785407bdcc31dbc8ba99e6a28c96d/nova/compute/api.py#L2894

-- 

Thanks,

Matt