On Mon, Dec 11, 2017 at 02:28:31PM +0000, Phill Bandelow wrote:
Hi,
We seem to be hitting an issue where libguestfs keeps hanging. virt-resize, guestmount etc.. never complete. If we set LIBGUESTFS_BACKEND_SETTINGS=force_tcg it completes.
The issue starts when updating to CentOS 7.4 (CentOS 7.3 work fine). It doesn't seem to affect all 7.4 hypervisors and the only similarity that we have found is that they all use NVMe drives.
I've seen this issue before where the UART hangs, and I can't put my finger on what was causing it right now. At any rate there's a few things you can look into: (1) Try with LIBGUESTFS_BACKEND=direct (without forcing TCG). (2) Is it using nested KVM? Is nested KVM enabled in the KVM module in the host kernel: # systool -m kvm_intel -v | grep nested (should say "Y" if yes) If nested KVM is enabled, you can disable it (probably requires a reboot unfortunately). Or if disabled, try enabling it. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v