1:47 a.m.
On Tue, Mar 6, 2018 at 7:54 PM, Yaniv Kaul <ykaul(a)redhat.com> wrote:
On Mar 6, 2018 7:02 PM, "Gianluca Cecchi" <gianluca.cecchi(a)gmail.com>
wrote:
Hello,
this thread last year (started by me... ;-) was very useful in different
aspects involved
http://lists.ovirt.org/pipermail/users/2017-March/080322.html
We did cover memory save or not and fsfreeze automatically done by guest
agent if installed inside the VM.
What about pre-snapshot scripts/operations to run inside guest, to have
application consistency?
Eg if I have a database inside the VM and I have scripted my backup job
involving live-snapshot (eg with the backup.py utility of the thread)
https://github.com/guillon/qemu-plugins/blob/master/scripts/
qemu-guest-agent/fsfreeze-hook.d/mysql-flush.sh.sample
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