Hello, Working me through documentation and articles I am totally lost on the matter. All I want to know is: - if issueing "openstack snapshot create ...." - if klicking "create Snaphost" in Horizon for an instance will secure a consistent snapshot (of all volumes in question). With "consistent", I mean that all the data in memory are written to the disc before starting a snapshot. I hope someone can clear up, if using the setup described in the following is sufficient to achieve this goal or if I have to do something in addition. If you have any question I am eager to answer as fast as possible. Setup: We have a Stein-based OpenStack deployment with cinder backed by ceph. Instances are created with cinder volumes. Boot volumes are based on an image having the properties: - hw_qemu_guest_agent='yes' - os_require_quiesce='yes' The image is ubuntu 16.04 or 18.04 with quemu-guest-agent package installed and service running (no additional configuration besides distro-default): qemu-guest-agent.service - LSB: QEMU Guest Agent startup script Loaded: loaded (/etc/init.d/qemu-guest-agent; bad; vendor preset: enabled) Active: active (running) since Wed 2019-08-14 07:42:21 UTC; 9min ago Docs: man:systemd-sysv-generator(8) CGroup: /system.slice/qemu-guest-agent.service └─2300 /usr/sbin/qemu-ga --daemonize -m virtio-serial -p /dev/virtio-ports/org.qemu.guest_agent.0 Aug 14 07:42:21 ulthwe systemd[1]: Starting LSB: QEMU Guest Agent startup script... Aug 14 07:42:21 ulthwe systemd[1]: Started LSB: QEMU Guest Agent startup script. I can see the socket on the compute node and send pings successfully: ~# ls /var/lib/libvirt/qemu/*.sock /var/lib/libvirt/qemu/org.qemu.guest_agent.0.instance-0000248e.sock root@pcevh2404:~# virsh qemu-agent-command instance-0000248e '{"execute":"guest-ping"}' {"return":{}} I can also send freeze and thaw successfully: ~# virsh qemu-agent-command instance-0000248e '{"execute":"guest-fsfreeze-freeze"}' {"return":1} ~# virsh qemu-agent-command instance-0000248e '{"execute":"guest-fsfreeze-thaw"}' {"return":1} Sending a simple write (echo "bla" > blub.file) in the "frozen" state will be blocked until "thaw" as expected. Best regards Ralf T.