Open Stack

Hi,

in my installation I'm going to use volumes to boot instances, not 
ephemeral disks. And I faced unexpected (for me, at least) behaviour 
when trying to implement snapshoting: image, created with "openstack 
server image create" can't be used for boot from volume, i.e.

I create image using "openstack server image create --name jsnap jex-n1" 
and then:

- creating server using ephemeral disk
* openstack server create jTest [ ... ] --image jsnap
is *OK*

- creating server usingvolume, populated from image:
* openstack volume create jVol --size 8 *--image jsnap* --bootable
* openstack server create jTest [ ... ] --volume jVol
*FAIL**S* with the following error: "_Invalid image metadata. Error: A 
list is required in field img_block_device_mapping, not a unicode (HTTP 
400)_".

- creating server using volume, populated from snapshot (which 
corresponds to the image):
* openstack volume create jVol --size 8 *--snapshot 
f0ad0bf0-97f4-49df-b334-71b9eb639567* --bootable
* openstack server create jTest [ ... ] --volume jVol
is *OK*

Assuming this is correct (oh, really? can't find this topic in 
documentation), I don't need image as it's senseless entity (I can't use 
it for booting from volumes) and just need snapshot. But I still like 
https://blueprints.launchpad.net/nova/+spec/quiesced-image-snapshots-with-qemu-guest-agent 
so there are two questions regarding this:

1) whether the following sequence will do exactly the same as "server 
image create" does? -
- "manually" freeze VM filesystem (using "guest-fsfreeze-freeze" command)
- create snapshot using "openstack volume snapshot create --volume 
<volume name> --force <snapshot name>"
- "manually" unfreeze VM filesystem (using "guest-fsfreeze-thaw" command)

2) and, when using Cinder API, is there way to synchronously wait for 
end of snapshot creation? It's useful in order to thaw filesystem 
immediately after snapshot will be done - neither after nor before few 
seconds.

Thanks.

-- 
Volodymyr Litovka
   "Vision without Execution is Hallucination." -- Thomas Edison

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack/attachments/20170906/88c5e307/attachment.html>