Re: [Libguestfs] Libguestfs Hangs on CentOS 7.4

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