<div dir="ltr">Thanks Rich.<div>I have used libguestfs for several month. It worked perfectly before, the issue appears recently. I am trying guestfs_set_backend (g, "direct").</div><div> </div><div>Thanks,</div><div>Allen</div></div><div class="gmail_extra"> <div class="gmail_quote">2016-08-29 23:31 GMT+08:00 Richard W.M. Jones <<a href="mailto:rjones@redhat.com" target="_blank">rjones@redhat.com</a>>: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Mon, Aug 29, 2016 at 11:19:04PM +0800, Baochuan Wu wrote: > Thanks Rich for you quick reply. I enabled logs and the program stuck > again, here is the call stack and log: > Thread 1 (Thread 0x7fac58edc8c0 (LWP 1271)): > #0 0x00007fac578fac20 in __poll_nocancel () from /lib64/libc.so.6 > #1 0x00007fac56df3c5a in virNetClientIOEventLoop () from > /lib64/libvirt.so.0 > #2 0x00007fac56df441b in virNetClientSendInternal () from > /lib64/libvirt.so.0 > #3 0x00007fac56df5843 in virNetClientSendWithReply () from > /lib64/libvirt.so.0 > #4 0x00007fac56df6052 in virNetClientProgramCall () from > /lib64/libvirt.so.0 > #5 0x00007fac56dcbfe2 in callFull.isra.2 () from /lib64/libvirt.so.0 > #6 0x00007fac56de213d in remoteDomainCreateXML () from /lib64/libvirt.so.0 > #7 0x00007fac56d82151 in virDomainCreateXML () from /lib64/libvirt.so.0 > #8 0x00007fac58acca50 in launch_libvirt () from /lib64/libguestfs.so.0 > #9 0x00007fac58ac2b2b in guestfs_impl_launch () from /lib64/libguestfs.so.0 > #10 0x00007fac58a5eba5 in guestfs_launch () from /lib64/libguestfs.so.0 > #11 0x00000000004117ca in main () ... > libguestfs: [62900ms] launch libvirt guest The error is happening in libvirt's virDomainCreateXML call, called from libguestfs here: <a href="https://github.com/libguestfs/libguestfs/blob/master/src/launch-libvirt.c#L600" rel="noreferrer" target="_blank">https://github.com/libguestfs/libguestfs/blob/master/src/launch-libvirt.c#L600</a> Unfortunately libvirt isn't a simple C library. It will launch and talk to a daemon (usually ``libvirt --timeout=30'' process, if you are not running as root). Debugging into libvirtd is described here: <a href="http://libguestfs.org/guestfs-faq.1.html#debugging-libvirt" rel="noreferrer" target="_blank">http://libguestfs.org/guestfs-faq.1.html#debugging-libvirt</a> A workaround is to set LIBGUESTFS_BACKEND=direct [or use the equivalent call ``guestfs_set_backend (g, "direct")''] which will cause libguestfs to run qemu directly instead of going through libvirt. <a href="http://libguestfs.org/guestfs.3.html#backend" rel="noreferrer" target="_blank">http://libguestfs.org/guestfs.3.html#backend</a> Rich. -- Richard Jones, Virtualization Group, Red Hat <a href="http://people.redhat.com/~rjones" rel="noreferrer" target="_blank">http://people.redhat.com/~rjones</a> Read my programming and virtualization blog: <a href="http://rwmj.wordpress.com" rel="noreferrer" target="_blank">http://rwmj.wordpress.com</a> virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. <a href="http://people.redhat.com/~rjones/virt-df/" rel="noreferrer" target="_blank">http://people.redhat.com/~rjones/virt-df/</a> </blockquote></div> </div>