I will note that we have several Windows 10 / Windows 2018 genre VM's on
Centos 7.8.2003 and are not seeing any guest freezes. But:
1) We are not using CPU host-passthrough.
2) We do have the QEMU Windows guest drivers installed in the VM's.
3) I am running Cloudstack 4.11.3. I tried upgrading to Cloudstack
4.14.0 and the upgrade failed, the agent was unable to ssh into virtual
routers to configure them.
That said, the version of Cloudstack should not matter, since all
Cloudstack does is tell libvirtd to launch the VM. libvirtd handles
everything from there. We are literally using the stock Centos 7.8
libvirtd.conf as modified by the agent configurator. I wonder if you
are having a hardware problem on your new server, or if there is a Linux
OS problem handling your new server. Use journalctl and see if you're
seeing anything at the Linux OS level when a freeze happens, and check
the qemu log files for the instance also, because normally libvirtd is
quite reliable and Centos 7.8.2003 supports Windows 10 VM's just fine.
On 8/9/2020 8:48 AM, Rohit Yadav wrote:
Hi Dave,
I've not specifically worked with Windows guest VMs on KVM, but what you've
described is largely subject to a guest OS support by the hypervisor, in this
case the specific libvirt/qemu/linux-kernel version and any guest tools/drivers
that must be installed inside the Windows guest VM. You've yourself
acknowledged that the issue is not seen in your older CentOS6 based environment.
To rule out CloudStack (a) you may add or upgrade hosts in a cluster to use
qemu-ev (enterprise qemu release by CentOS SIG
https://wiki.centos.org/SpecialInterestGroup/Virtualization, i.e. install the
centos-release-qemu-ev pkg) or (b) you may add a new cluster with Ubuntu 18.04
KVM hosts and recreate your Windows VM setup. Or, it could be a specific
Windows build or requires additional drivers (such as
https://www.linux-kvm.org/page/WindowsGuestDrivers/Download_Drivers).
Hope this helps.
Regards.
________________________________
From: Dave Lapointe <[email protected]>
Sent: Saturday, August 8, 2020 00:48
To: [email protected] <[email protected]>
Subject: Windows 10 KVM becoming inaccessible
Hi,
I've been lurking on this group for a few years now and have found the
information that people have posted here to be quite helpful for me to
understand CloudStack better. I've never replied here because there are always
far more knowledgeable people on this list who can offer much better insight
than I ever could.
An issue has arisen recently that I can't find any solution for. I apologize
ahead of time if this is the wrong list to post to.
I recently configured a new server to run CloudStack using Centos 7.8.2003 and CloudStack
4.14, and configured some Windows 10 LTSB KVM guests. This is a fairly specialized
server, so the configuration is a little unusual. It's configured to use the
"cloudbr0" software bridge for the guest network which is then routed
externally through a single NIC. Also, because the VM's will never be migrated, I've set
guest.cpu.mode=host-passthrough.
What's been happening though is that the VM's will just freeze sometimes,
apparently randomly. Sometimes it will happen during boot, or a couple minutes
after connecting by RDP. And sometimes the VM won't freeze at all. I haven't
been able to determine a pattern as to when this will happen. And I haven't
found anything in the logs that might help me understand what's happening
(/var/log/messages and /var/log/cloudstack/management/management-server.log).
I've checked on the QEMU and Linux forums, but have only found a bit of
information about VM's freezing for people using specific graphics drivers with
passthrough for their graphics cards. I tried removing
guest.cpu.mode=host-passthrough but that made no difference.
What's especially odd to me is that this didn't happen with older systems I've
created (eg. CentOS 6 and CloudStack 4.9). I've setup half a dozen or so using
the same configuration as this system, just older software.
I can't tell if this is related to CloudStack (maybe there is something in the
guest parameters that is causing this), or if this is strictly a KVM issue.
And since I can't find anything in the logs I don't know where else to look.
I'm hoping to get some suggestions from this list so that I can do some more
digging.
Thanks,
Dave
[email protected]
www.shapeblue.com
3 London Bridge Street, 3rd floor, News Building, London SE1 9SGUK
@shapeblue
