[libvirt] Failed to terminate process 1275 with SIGTERM: Device or resource busy

I didn't file a bug about this because it's not really clear what the bug is. Anyway, here goes ... $ virt-builder fedora-23 -o /dev/sdX [ 2.3] Downloading: http://libguestfs.org/download/builder/fedora-23.xz [ 3.0] Planning how to build this image [ 3.0] Uncompressing [ 18.1] Resizing (using virt-resize) to expand the disk to 14.9G virt-resize: error: libguestfs error: could not destroy libvirt domain: Failed to terminate process 1275 with SIGTERM: Device or resource busy [code=38 domain=0] $ ps ax | grep qemu 1275 ? Dl 0:49 /usr/bin/qemu-system-x86_64 -machine accel=kvm [...] What's actually happening here is that /dev/sdX is an incredibly slow[1] USB key. The virt-resize operation completes successfully, but qemu is blocked writing/fsyncing to the USB key, and takes a few minutes to exit. libvirt has a loop (src/util/virprocess.c:virProcessKillPainfully) which waits 15 seconds [comment says 10 seconds], and this wait is not configurable. There seem to be several possible solutions, none of them very nice: - Hard-code a longer wait in libvirt. - Make the wait in libvirt configurable. - If the process is in 'D' state, wait indefinitely. I tried another workaround which was to get virt-resize to fsync the output file before closing the libvirt connection, but that doesn't work for reasons I don't understand so far - still studying this. Rich. [1] "Incredibly slow" ... but it's just a regular USB key, they are all very slow! -- 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