libvirt users - Jan 2014 - Re: running LXC hello world example

Hello,

I am having difficulty getting any sort of LXC container running.  I am
trying to use the following tutorial to run the hello world example:

https://www.berrange.com/posts/2011/09/27/getting-started-with-lxc-using-libvirt/


Here are the results of my running the tutorial:

[root@terraria ~]# virsh list
 Id    Name                           State
----------------------------------------------------

[root@terraria ~]# virsh uri
lxc:///

[root@terraria ~]# cat helloworld.xml
<domain type='lxc'>
  <name>helloworld</name>
  <memory>102400</memory>
  <os>
    <type>exe</type>
    <init>/bin/sh</init>
  </os>
  <devices>
    <console type='pty'/>
  </devices>
</domain>
[root@terraria ~]# virsh define helloworld.xml
Domain helloworld defined from helloworld.xml

[root@terraria ~]# virsh start helloworld
error: Failed to start domain helloworld
error: internal error guest failed to start: PATH=/bin:/sbin TERM=linux
container=lxc-libvirt container_uuid=791640de-95a9-082c-7292-c55106bcdca9
LIBVIRT_LXC_UUID=791640de-95a9-082c-7292-c55106bcdca9
LIBVIRT_LXC_NAME=helloworld /bin/sh
error receiving signal from container: Input/output error

---

As you can see, I am getting an error.  How do I go about diagnosing this
error?  This is a fresh install so the only thing I have been using this
machine for is for LXC/libvirt testing.

-- 
Jacob Everist

cell:  310-425-9732
email:  jacob.everist@gmail.com

Some more details on my system.

I am running CentOS 6.5.   To install libvirt and LXC, I performed the
following command:

yum install libvirt libvirt-client python-virtinst

I have turned selinux to DISABLED.



On Wed, Jan 22, 2014 at 10:34 AM, Jacob Everist
<jacob.everist@gmail.com>wrote:
> Hello,
>
> I am having difficulty getting any sort of LXC container running.  I am
> trying to use the following tutorial to run the hello world example:
>
>
>
https://www.berrange.com/posts/2011/09/27/getting-started-with-lxc-using-libvirt/
>
>
> Here are the results of my running the tutorial:
>
> [root@terraria ~]# virsh list
>  Id    Name                           State
> ----------------------------------------------------
>
> [root@terraria ~]# virsh uri
> lxc:///
>
> [root@terraria ~]# cat helloworld.xml
> <domain type='lxc'>
>   <name>helloworld</name>
>   <memory>102400</memory>
>   <os>
>     <type>exe</type>
>     <init>/bin/sh</init>
>   </os>
>   <devices>
>     <console type='pty'/>
>   </devices>
> </domain>
> [root@terraria ~]# virsh define helloworld.xml
> Domain helloworld defined from helloworld.xml
>
> [root@terraria ~]# virsh start helloworld
> error: Failed to start domain helloworld
> error: internal error guest failed to start: PATH=/bin:/sbin TERM=linux
> container=lxc-libvirt container_uuid=791640de-95a9-082c-7292-c55106bcdca9
> LIBVIRT_LXC_UUID=791640de-95a9-082c-7292-c55106bcdca9
> LIBVIRT_LXC_NAME=helloworld /bin/sh
> error receiving signal from container: Input/output error
>
> ---
>
> As you can see, I am getting an error.  How do I go about diagnosing this
> error?  This is a fresh install so the only thing I have been using this
> machine for is for LXC/libvirt testing.
>
> --
> Jacob Everist
>
> cell:  310-425-9732
> email:  jacob.everist@gmail.com
>


-- 
Jacob Everist

cell:  310-425-9732
email:  jacob.everist@gmail.com

On 01/22/2014 11:42 AM, Jacob Everist wrote:
> Some more details on my system.
> 
> I am running CentOS 6.5.   To install libvirt and LXC, I performed the
> following command:
That may be your problem.  LXC is not very well supported in RHEL 6 (it
was marked as a technology preview, which means Red Hat is not
supporting it - and CentOS just adds another layer of non-support).
There has been LOTS of upstream work on LXC in the meantime (RHEL 6 uses
libvirt 0.10.2, and upstream is now at 1.2.1).  You probably want to try
rebuilding libvirt from upstream tarballs, and/or trying the RHEL 7
beta, before trying anything serious with libvirt LXC support.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

On Wed, Jan 22, 2014 at 10:42:15AM -0800, Jacob Everist
wrote:
> Some more details on my system.
> 
> I am running CentOS 6.5.   To install libvirt and LXC, I performed the
> following command:
> 
> yum install libvirt libvirt-client python-virtinst
> 
> I have turned selinux to DISABLED.
When you say disabled, do you actually mean you booted with selinux=0
or do you just mean you set it to permissive.

In RHEL-6 there was a bug that could break LXC if you boot with selinux=0.

Running with selinux enabled, but in permissive mode should work just
fine though.

> On Wed, Jan 22, 2014 at 10:34 AM, Jacob Everist
<jacob.everist@gmail.com>wrote:
> 
> > Hello,
> >
> > I am having difficulty getting any sort of LXC container running.  I
am
> > trying to use the following tutorial to run the hello world example:
> >
> >
> >
https://www.berrange.com/posts/2011/09/27/getting-started-with-lxc-using-libvirt/
> >
> >
> > Here are the results of my running the tutorial:
> >
> > [root@terraria ~]# virsh list
> >  Id    Name                           State
> > ----------------------------------------------------
> >
> > [root@terraria ~]# virsh uri
> > lxc:///
> >
> > [root@terraria ~]# cat helloworld.xml
> > <domain type='lxc'>
> >   <name>helloworld</name>
> >   <memory>102400</memory>
> >   <os>
> >     <type>exe</type>
> >     <init>/bin/sh</init>
> >   </os>
> >   <devices>
> >     <console type='pty'/>
> >   </devices>
> > </domain>
> > [root@terraria ~]# virsh define helloworld.xml
> > Domain helloworld defined from helloworld.xml
> >
> > [root@terraria ~]# virsh start helloworld
> > error: Failed to start domain helloworld
> > error: internal error guest failed to start: PATH=/bin:/sbin
TERM=linux
> > container=lxc-libvirt
container_uuid=791640de-95a9-082c-7292-c55106bcdca9
> > LIBVIRT_LXC_UUID=791640de-95a9-082c-7292-c55106bcdca9
> > LIBVIRT_LXC_NAME=helloworld /bin/sh
> > error receiving signal from container: Input/output error
> >
> > ---
> >
> > As you can see, I am getting an error.  How do I go about diagnosing
this
> > error?  This is a fresh install so the only thing I have been using
this
> > machine for is for LXC/libvirt testing.
You can try looking at /var/log/libvirt/lxc/$GUEST.log


if that has insufficient info, then you can do

  service libvirtd stop
  edit /etc/libvirt/lxc.conf and set  log_with_libvirtd=1
  LIBVIRT_LOG_FILTERS=1:lxc LIBVIRT_LOG_OUTPUTS=1:stderr /usr/sbin/libvirt

and then start the guest - the guest log file should then have much more
info in it.

Daniel
-- 
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