Hyper-V: Fixes disk overhead claim issue

For each started VM, Hyper-V creates a VM memory file on the local
disk. The size of the file is the same as the size of the VM's
memory amount.

Implements the mentioned method in HyperVDriver.

Change-Id: Id40219dae96c0f7e60a86c0ed76fa08cea608aec
Closes-Bug: #1505681

1 files changed, 8 insertions, 0 deletions

diff --git a/nova/virt/hyperv/vmops.py b/nova/virt/hyperv/vmops.py
index 49f39b1723..4187a0a4fc 100644
--- a/nova/virt/hyperv/vmops.py
+++ b/nova/virt/hyperv/vmops.py
@@ -131,6 +131,14 @@ class VMOps(object):
     def list_instances(self):
         return self._vmutils.list_instances()
 
+    def estimate_instance_overhead(self, instance_info):
+        # NOTE(claudiub): When an instance starts, Hyper-V creates a VM memory
+        # file on the local disk. The file size is the same as the VM's amount
+        # of memory. Since disk_gb must be an integer, and memory is MB, round
+        # up from X512 MB.
+        return {'memory_mb': 0,
+                'disk_gb': (instance_info['memory_mb'] + 512) // units.Ki}
+
     def get_info(self, instance):
         """Get information about the VM."""
         LOG.debug("get_info called for instance", instance=instance)