[Openstack] Error mounting disk with libguestfs (child process died unexpectedly)

Arindam Choudhury arindam at live.com
Wed Mar 5 13:28:43 UTC 2014


the permission of /dev/kvm:

crw-rw-rw-+ 1 root kvm 10, 232 Mar  4 14:28 /dev/kvm

From: parthipan at hp.com
To: arindam at live.com; openstack at lists.openstack.org
Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)
Date: Wed, 5 Mar 2014 13:23:41 +0000









What are /dev/kvm permissions?
 
 



From: Arindam Choudhury [mailto:arindam at live.com]


Sent: 05 March 2014 11:09

To: Parthipan, Loganathan; openstack at lists.openstack.org

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)


 

Which user I must add in root group? nova or qemu?




From: parthipan at hp.com

To: arindam at live.com; openstack at lists.openstack.org

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)

Date: Wed, 5 Mar 2014 10:12:14 +0000

Seems like qemu doesn’t have the privileges to read
/sys/kernel/debug/tracing/tracing_on
 
 
 



From: Arindam Choudhury [mailto:arindam at live.com]


Sent: 04 March 2014 15:15

To: Parthipan, Loganathan; openstack at lists.openstack.org

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)


 

Hi,

both
/sys/kernel/debug/tracing/tracing_on
/sys/kernel/debug/tracing/events/kvm/enable is 1.
 
The logs are:


libvirtd-debug (sorry for lots of garbage in this file)



/var/log/messages



instance.log



After disabling tracing_on and tracing kvm events, it gave the same error.



Regards,

Arindam




From: parthipan at hp.com

To: arindam at live.com

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)

Date: Tue, 4 Mar 2014 14:07:31 +0000

If you can that’ll be great. Thanks.

 
Also what’s in
 
/sys/kernel/debug/tracing/tracing_on
/sys/kernel/debug/tracing/events/kvm/enable
 
Try running after
echo 0 > /sys/kernel/debug/tracing/tracing_on
 
If there’s no improvement try - although I don’t know what it really does (I need to read the code)
echo 0 > /sys/kernel/debug/tracing/events/kvm/enable
 
I’m just wondering if it’s due to some permission/ACL issues when trying to write into debugfs using ftrace, given your observation on different tracing backends.
 
Thanks for reporting and spending time on this.
 
Cheers
~parthi
 
 



From: Arindam Choudhury [mailto:arindam at live.com]


Sent: 04 March 2014 13:27

To: Parthipan, Loganathan

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)


 

Hi,



Its a multi-node deployment with nova-network.



If you want I can recreate the error and send you the logs.



Regards,




From: parthipan at hp.com

To: arindam at live.com

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)

Date: Tue, 4 Mar 2014 13:21:24 +0000

Interesting…
 
Is it a single node deployment? Do you have any other log data such as libvirt_debug.log, libvirt/qemu/instance-xxxx.log? Any errors/warnings during the time
 of instance creation in syslog?
 



From: Arindam Choudhury [mailto:arindam at live.com]


Sent: 04 March 2014 12:56

To: Parthipan, Loganathan

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)


 



it only happens when I enable 
--enable-trace-backend=ftrace

with 
--enable-trace-backend=simple

works fine.




From: parthipan at hp.com

To: arindam at live.com

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)

Date: Tue, 4 Mar 2014 12:33:55 +0000

Also check if it’s a cgroups issue since the binary location changed. You could look at the syslog and kern.log
 
 



From: Parthipan, Loganathan


Sent: 04 March 2014 12:15

To: 'Arindam Choudhury'; openstack at lists.openstack.org

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)


 
Reading your log, I don’t think the problem is due to injection failure at libguestfs. It’s a warning and is ignored.
 
Seems more like a network setup issue. Are you using neutron? Is the network/subnet etc setup properly?
 



From: Arindam Choudhury [mailto:arindam at live.com]


Sent: 04 March 2014 11:50

To: Parthipan, Loganathan; openstack at lists.openstack.org

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)


 

Hi Parthipan,



When I try to do yum remove python-libguestfs.

It also wants to remove openstack-nova-compute. So, I can not.



Regards,

Arindam




From: parthipan at hp.com

To: arindam at live.com; openstack at lists.openstack.org

Subject: RE: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)

Date: Tue, 4 Mar 2014 11:23:50 +0000

Arindam,
 
What happens if you ‘apt-get remove python-guestfs’ and try? I’d expect it to fallback to nbdmount.
 
 



From: Arindam Choudhury [mailto:arindam at live.com]


Sent: 04 March 2014 10:40

To: openstack at lists.openstack.org

Subject: [Openstack] Error mounting disk with libguestfs (child process died unexpectedly)


 

Hi,

I have a working Openstack Grizzly setup with nova-network on Scientific Linux. As, SL comes with a old qemu:
qemu-kvm-0.12.1.2-2.355.el6_4.6.x86_64

I am trying to upgrade it to qemu-1.7.0 from source. 

The configuration output.

As, openstack use /usr/libexec/qemu-kvm to start up VM, i linked 
qemu-kvm to qemu-system-x86_64:
ls
-l
/usr/libexec/qemu-kvm
 lrwxrwxrwx 1 root root
33
Feb
19
15:25
/usr/libexec/qemu-kvm
->
/usr/local/bin/qemu-system-x86_64

But when I try to start VM, I get following error:

WARNING nova.virt.disk.api [req-7dfd6cf1-db21-403d-abbf-ccb5f0273a6a 
b829b65d0675416198f9e4838b5009e2 9a2e060772204260b53b52ea1c12db97] 
Ignoring error injecting data into image 
(Error mounting /var/lib/nova/instances/07c0898e-7d75-448d-b4fe-2c37f681b846/disk 
with libguestfs (child process died unexpectedly))

The full error log is here.

Output of libguestfs-test-tool is here.

Regards,























 		 	   		  
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