Libguestfs - Mar 2016 - Re: virt-v2v become zombie via python cpopen on error

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:
    c = p.stdout.read(1)
    print c
----------------------------------------------------------------------------

Thanks,
  Shahar Havivi.

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:
>     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.

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

> On 30 Mar 2016, at 11:49, Richard W.M. Jones <rjones@redhat.com>
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:
>>    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