Re: [ovirt-devel] virt-v2v become zombie via python cpopen on error

On 30.03.16 14:28, Nir Soffer wrote: > On Wed, Mar 30, 2016 at 1:36 PM, Michal Skrivanek > <michal.skrivanek(a)redhat.com&gt; wrote: > > > >> On 30 Mar 2016, at 11:49, Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: > >> > >> On Wed, Mar 30, 2016 at 12:19:35PM +0300, Shahar Havivi wrote: > >>> Hi, > >>> > >>> We encounter a problem in VDSM project that virt-v2v become zombie task while > >>> importing vm from vmware. > >>> When virt-v2v is in 'copy disk' mode and we someone deletes the vm at vmware > >>> the process hang in read() method, > >>> I am pretty sure that its not virt-v2v problem because when I run it from the > >>> shell virt-v2v exit with an error, still maybe someone have an idea.... > >>> > >>> I wrote a small python script that encounter the problem: > >>> > >>> ---------------------------------------------------------------------------- > >>> from cpopen import CPopen > >>> > >>> env = {'LIBGUESTFS_BACKEND': 'direct'} > >>> cmd = ['/usr/bin/virt-v2v', '-ic', > >>> 'vpx://....', '-o', > >>> 'local', '-os', '/tmp', '-of', 'raw', '-oa', 'sparse', > >>> '--password-file', '/tmp/passwd', '--machine-readable', 'bbb'] > >>> p = CPopen(cmd, env=env) > >>> while p.returncode is None: > > p.returncode just return the instance variable, there is no wait() involved. > > The right way: > > while p.poll() is None: the problem is proc.stdout.read(1) didn't raise and error when the stream closed but return ''. its a CPopen behaviour and works differently in subprocess.

> ... > > p.returncode calling wait is non-standard feature in vdsm AsyncProc > wrapper. This is > the object used by v2v vdsm module, so there accessing p.returncode does call > p.poll(). > > These non-standard apis will be removed from vdsm, please do not use them. > > >>> c = p.stdout.read(1) > >>> print c > >>> ---------------------------------------------------------------------------- > >> > >> An actual zombie task? That would indicate that the parent process > >> (your Python program) wasn't doing a wait system call. > >> > >> I downloaded the cpopen-1.4 program, and it doesn't appear to call any > >> of the wait*(2) system calls anywhere, so that could be the problem. > > > > I suppose the cpopen parameters are not alright…I’m sure vdsm developers can help with that. > > > >> > >> 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 > > > > _______________________________________________ > > Devel mailing list > > Devel(a)ovirt.org > > http://lists.ovirt.org/mailman/listinfo/devel