[virt-tools-list] Re: [libvirt] Create a new VM from an existent image?

[Jun Koi]

On Tue, Jul 21, 2009 at 11:40 AM, Cole Robinson<crobinso at redhat.com> wrote:
> Jun Koi wrote:
>> On Tue, Jul 21, 2009 at 11:07 AM, Jun Koi<junkoi2004 at gmail.com> wrote:
>>> On Tue, Jul 21, 2009 at 10:45 AM, Jun Koi<junkoi2004 at gmail.com> wrote:
>>>> On Mon, Jul 20, 2009 at 1:19 AM, Cole Robinson<crobinso at redhat.com> wrote:
>>>>> (taking to virt-tools-list, this isn't relevant to libvirt)
>>>>>
>>>>> Jun Koi wrote:
>>>>>> On Sun, Jul 19, 2009 at 1:59 AM, Cole Robinson<crobinso at redhat.com> wrote:
>>>>>>> Jun Koi wrote:
>>>>>>>> On Fri, Jul 17, 2009 at 10:42 PM, Cole Robinson<crobinso at redhat.com> wrote:
>>>>>>>>> Jun Koi wrote:
>>>>>>>>>> Hi,
>>>>>>>>>>
>>>>>>>>>> To use libvirt, I am strying to use virt-install to create a new VM
>>>>>>>>>> from an existent (KVM) VM image. I did the following steps:
>>>>>>>>>>
>>>>>>>>>> 1) run libvirtd with "libvirtd -d" (I use the latest libvirt git tree)
>>>>>>>>>>
>>>>>>>>>> 2) Run virt-install (0.400.3) with my existent image in img/img.winxp
>>>>>>>>>>
>>>>>>>>>> # virt-install --import -n winxp -f img/img.xp3 --vnc --hvm
>>>>>>>>>> --accelerate --ram 800
>>>>>>>>>>
>>>>>>>>> That looks fine.
>>>>>>>>>
>>>>>>>>>> However, this step returns error like:
>>>>>>>>>>
>>>>>>>>>> "ERROR    Could not find usable default libvirt connection."
>>>>>>>>>>
>>>>>>>>> If 'virsh --connect qemu:///system' doesn't work, you probably didn't
>>>>>>>>> configure your libvirt install correctly.
>>>>>>>>>
>>>>>>>> But it works! So the problem stays elsewhere.
>>>>>>>>
>>>>>>>> Do you have any suggestion?
>>>>>>>>
>>>>>>> Hmm, then you probably need this patch to virtinst, since our URI detection
>>>>>>> likely isn't as thorough as libvirt:
>>>>>>>
>>>>>>> http://hg.et.redhat.com/cgi-bin/hg-virt.cgi/applications/virtinst--devel/rev/030fbc6df74f
>>>>>>>
>>>>>> I got the latest code from hg tree, and installed that.  But running
>>>>>> "virt-install" (without option) returns the error message:
>>>>>>
>>>>>> Traceback (most recent call last):
>>>>>>   File "/usr/local/bin/virt-install", line 36, in <module>
>>>>>>     from virtinst.VirtualCharDevice import VirtualCharDevice
>>>>>> ImportError: No module named VirtualCharDevice
>>>>>>
>>>>>>
>>>>>>
>>>>>> How to fix this problem?
>>>>>>
>>>>> There must be an install issue, you shouldn't have this issue. My guess is
>>>>> /usr/local/bin/virt-install isn't looking at the newly installed virtinst libs.
>>>>>
>>>>> What command did you use to install? What distro are you on? What does:
>>>>>
>>>>> python -c 'import virtinst; print virtinst'
>>>>>
>>>>> show? It should list the path to the newly installed virtinst, the one via
>>>>> your distro.
>>>> It prints out: <module 'virtinst' from 'virtinst/__init__.py'>""
>>>>
>>>> I checked again, and see that virt-install was installed into
>>>> /usr/local/bin, which might not be the right place? It should be in
>>>> /usr/bin, right? So how to install virt-install there?
>>>>
>>>> If that matters, I install virt-install by running "python setup.py
>>>> install". I am on Ubuntu 904, and I heard that Python 2.6.2 on this
>>>> distro has some problems with installation, so that they always put
>>>> code into /usr/local/ (??)
>>> I tried to install virt-install again, with command:
>>>
>>> python setup.py install --prefix=/usr
>>>
>>> Then I run "virt-install" again (without option). This time I got the
>>> below error:
>>>
>>> Traceback (most recent call last):
>>>  File "/usr/bin/virt-install", line 36, in <module>
>>>    from virtinst.VirtualCharDevice import VirtualCharDevice
>>> ImportError: No module named VirtualCharDevice
>>>
>>>
>>> So it is still the same problem as before. Do you have any hint?
>>>
>>> My impression is that so far, libvirt stuff is not well supported in
>>> Ubuntu, but only in Fedora Core.
>>
>> I had another attempt on another Ubuntu (8.04), and it seems to work
>> this time. Ubuntu 804 use older Python 2.5.2, and that makes the
>> difference?
>>
>
> Not sure exactly. Sounds like the newer Ubuntu version changed how python
> packages are installed by default, and something is slipping up. The above
> error message likely means that 'virt-install' couldn't find the newly
> installed virtinst libs. Maybe a PYTHONPATH problem?
>
> Either way, if you find out how to install virtinst from source on the newer
> ubuntu version, let us know.
>
>> However, when I run the below command to import an existent KVM image:
>>
>> virt-install --import -n xp3 -f img/img.xp3 --vnc --hvm --accelerate
>> --ram 1000 --prompt
>>
>> I got the question: "How large would you like the disk img/img.xp3 to be?"
>>
>> This is really confused to me: it seems virt-install is trying to
>> create a new image, while all i want to do is to *import* image (I
>> already specified --import above), but not to create a new one.
>>
>> How to fix this?
>>
>
> I'm not sure, I can't reproduce on my system with a latest checkout. Does that
> file path definitely exist? Can you attach the output of that command with the
> --debug flag?
>

It seems that the problem is because I didnt give the full path to the
existent image above?

I tried again, this time give virt-install the full path to the image,
and it seems to work now.

Is it better if virt-install can figure it out the full path, even if
we specify the relative path?

> Also, if you are importing an XP image, you will probably want to specify
> --os-variant winxp to get the proper defaults.
>

How does this help, and what virt-install does with --os-variant option here??

Thanks,
J