Open Stack

Hi all,

I am practicing how to install openstack in terms of the toturial from 
the openstack official website. When creating image, I encountered a 
problem concerning the permission to create image files. At first, the 
'/var/lib/glance/images' directory was choosen to store image files. For 
this case, everything is good. After a while, however, I think there 
should be more space to store image files. So, I invorked 'fdisk' to 
allocate a partition from the free space of hard disk. Then, a ext4 file 
system was created in this new partition, and mounted at the 
'/var/lib/glance/images' directory. When creating a image, the glance 
service reported the following message:

503 Service Unavailable: Insufficient permissions on image storage 
media: Permission to write image storage media denied. (HTTP 503)

With some advices from Internet, I change the owner and group of the 
'/var/lib/glance/images' directory and its subdirectories using the 
following command:

chown -R glance:glance /var/lib/glance/images

But, this practice does not have any effect. Any suggestion? Thanks in 
advance.