KVM - Virsh External Backup "ERROR"

Hey everyone!

I just tried to make a Backup / Snapshot from a VM typing this command:

"virsh blockcopy $VMNAME $DEVICENAME $LOCALBACKUPPATH$VMNAME.qcow2 --wait --finish --verbose"

I did then get this Error:

"kvm error: internal error: unable to execute QEMU command 'drive-mirror': Could not create file: Permission denied"

Any idea? I searched the web and found some stuff about it but nothing actually helped me solve the problem..

Thanks alot