Permission Denied While Starting VM Instance in Openstack

As I was building Openstack Lab, I happen to encounter error message as it was seen on a log file from.tail -f /var/log/nova/nova-compute.log

$ tail -f /var/log/nova/nova-compute.log 
2016-03-21 22:05:34.283 1228 ERROR oslo_messaging.rpc.dispatcher     rv = meth(*args, **kwargs)
2016-03-21 22:05:34.283 1228 ERROR oslo_messaging.rpc.dispatcher   File "/usr/lib64/python2.7/site-packages/libvirt.py", line 1059, in createWithFlags
2016-03-21 22:05:34.283 1228 ERROR oslo_messaging.rpc.dispatcher     if ret == -1: raise libvirtError ('virDomainCreateWithFlags() failed', dom=self)
2016-03-21 22:05:34.283 1228 ERROR oslo_messaging.rpc.dispatcher libvirtError: internal error: process exited while connecting to monitor: 2016-03-22T02:05:33.427711Z qemu-kvm: -chardev file,id=charserial0,path=/var/lib/nova/instances/0b79cc65-c530-4e55-99b8-157524033d14/console.log: Could not open '/var/lib/nova/instances/0b79cc65-c530-4e55-99b8-157524033d14/console.log': Permission denied

This error came up when tried to start an instance that has been created earlier.

### With openstack CLI ###
$ openstack server start 

### With nova command ###
$ sudo nova start 

Apparently, I had had some issues manually starting kvm machines so I had played around with this file /etc/libvirt/qemu.conf

user="qemu"
group="qemu"
dynamic_ownership=0

To prevent this error revert the changes to:

sudo systemctl stop libvirtd

Edit qemu.conf file:

sudo vim /etc/libvirt/qemu.conf

Set the following

user="nova"
group="nova"
dynamic_ownership=1

Save the file then restart the libvirt daemon

sudo systemctl restart libvirtd

You should now be able to start Openstack Instance on your compute nodes.