On Tue, Mar 6, 2018 at 7:54 PM, Yaniv Kaul <ykaul(a)redhat.com&gt; wrote: Hello Yaniv, thanks for the information and the example file link. So I have understood that the freeze-hook script is run with the "freeze" option before snapshot and again but with the "thaw" option after the snapshot. So I can manage what to do, parsing the argument given So far so good. I have tested with a Fedora 27 guest and all is ok there. Now I would like to do something similar for a Windows 2008 R2 x64 VM. I see that the qemu-guest-agent has been installed under C:\Programs\qemu-ga and that the "QEMU Guest Agent" service is run as "C:\Program Files\qemu-ga\qemu-ga.exe" -d In fact I see I have a registry key in HKLM\SYSTEM\CurrentControlSet\services\QEMU-GA with the same value above for ImagePath ; "C:\Program Files\qemu-ga\qemu-ga.exe" -d What should I do to enable a freeze-hook script on Windows now? BTW: searching around while trying to understand more, I found that: on hypervisor running the VM I have # vdsClient -s 0 getVmStats vm_guid that works and gives me information that confirms agent seems to communicate and I get also appsList = [.... , 'QEMU guest agent', ...] Also, the dump of the dynamic xml for the guest contains # virsh -r dumpxml VM_NAME <channel type='unix'> <source mode='bind' path='/var/lib/libvirt/qemu/channels/420e5014-9b26-a4c0-9d79-ed9b123304de.org.qemu.guest_agent.0'/> <target type='virtio' name='org.qemu.guest_agent.0' state='connected'/> <alias name='channel1'/> <address type='virtio-serial' controller='0' bus='0' port='2'/> </channel> I tried to get its settings from qemu guest agent using socat and unix domain sockets but I don't receive answer # socat unix-connect:/ var/lib/libvirt/qemu/channels/420e5014-9b26-a4c0-9d79-ed9b123304de.org.qemu.guest_agent.0 readline and then in the interactive prompt {"execute":"guest-info"} to get and verify information about fsfreeze, something like ...., {"enabled": true, "name": "guest-fsfreeze-freeze"}, ... ...., {"enabled": true, "name": "guest-fsfreeze-thaw"}, ... But I didn't get any line.... Is this communication from OS disabled by design out of oVirt mgmt? Thanks again for any info to configure freeze-hook in Windows guest. Gianluca

On Thu, Mar 8, 2018 at 9:47 AM, Yaniv Kaul <ykaul(a)redhat.com&gt; wrote: Yes, I see that there are some VSS events intercepted in event viewer when I run a snapshot. But in my particulr case I have an Oracle database used for Business Intelligence that for performance reasons is not in archive log mode, so it can't interact with VSS layer. Due to its nature I can shutdown this database during the evening and then reopen it before the ETL processing happens during the night. So in that time frame I would like to have a pre-snapshot operation of shutdown db and post-snapshot operation of start db. And then I clone the snapshot and export it in case I have to restore the "blob" as a consistent whole It is for this reason that I'm trying to verify if the freeze-hook is usable also in WIndows environments (based on some threads I find it should be...) Thanks, Gianluca