<div dir="ltr"><div class="gmail_quote"><div dir="ltr">On Thu, May 4, 2017 at 11:09 PM Michal Skrivanek <<a href="mailto:michal.skrivanek@redhat.com">michal.skrivanek@redhat.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
> On 4 May 2017, at 17:51, Gianluca Cecchi <<a href="mailto:gianluca.cecchi@gmail.com" target="_blank">gianluca.cecchi@gmail.com</a>> wrote:<br>
><br>
> Hello,<br>
> supposing to have a Linux VM with ovirt-guest-agent installed, </blockquote><div><br></div><div>File system freezing is implemented using libvirt fsFreese/fsThaw, and is</div><div>implemented in the guest with qemu-guest-agent, not ovirt-guest-agent.</div><div><br></div><div>You can find the info on using it here:</div><div><a href="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Virtualization_Deployment_and_Administration_Guide/sect-Using_the_QEMU_guest_virtual_machine_agent_protocol_CLI-libvirt_commands.html">https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Virtualization_Deployment_and_Administration_Guide/sect-Using_the_QEMU_guest_virtual_machine_agent_protocol_CLI-libvirt_commands.html</a><br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">during a live snapshot operation it should be freeze of filesystems.<br>
> Where to find confirmation of correct/successful interaction?<br>
<br>
if it’s not successful there should be an event log message about that. And prior to taking the snapshot a warning in red at the bottom of the dialog (that check happens when you open the dialog, so it may not be 100% reliable)<br>
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> /var/log/messages or agent log or other kind of files?<br>
<br>
if you want to doublecheck then this is noticable in vdsm.log. First we try to take the snapshot with fsfreeze, and only when it fails we take it again without it.<br></blockquote><div><br></div><div>Since 3.6 we use fsFreeze/fsThaw explicitly, so we don't try snapshot twice.</div><div><br></div><div>In vdsm log you will find an INFO log before/after fsFreeze/fsThaw, or WARN log if they failed.</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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> Are there any limitations on filesystems that support freeze? Is it fsfreeze the command executed at VM OS level or any other low level command?<br>
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It’s a matter of Linux and Windows implementation, they both have an API supporting that at kernel level. I’m not aware of filesystem limitations.<br></blockquote><div><br></div><div>You should check qemu-guest-agent documentation.</div><div><br></div><div>Nir </div></div></div>