[ovirt-users] Cannot run VM. Low disk space on target Storage Domain local_storage.

I have successfully installed my VM however suddenly when I log out ovirt-engine then need to run again the VM and it give me error message "Cannot run VM. Low disk space on target Storage Domain local_storage." I am sure that I did not change any setting just run another one vm to try it out... Here are the specification for local storage Size: 49 GB Available: 4 GB Used: 45 GB Allocated: 2 GB Over Allocation Ratio: 25% Any help would be very much appreciate...