Merge pull request #6 from stackhpc/raid-size

Calculate RAID size_mb parameter correctly

Author: priteau

library/drac.py

@@ -543,6 +543,19 @@ def _determine_initial_state(self, goal_vdisks):
 
         self.set_initial_state(changing, pending, conflicting)
 
+    @staticmethod
+    def _compute_size_mb(goal_vdisk, min_size_mb):
+        raid_level = str(goal_vdisk['raid_level'])
+        if raid_level in ('6', '6+0'):
+            parity_disks_per_span = 2
+        elif raid_level in ('5', '5+0'):
+            parity_disks_per_span = 1
+        else:
+            parity_disks_per_span = 0
+        length = goal_vdisk['span_length'] - parity_disks_per_span
+        effective_length = 1 if raid_level in ('1', '1+0') else length
+        return min_size_mb * effective_length * goal_vdisk['span_depth']
+
     def _determine_required_changes(self, goal_vdisks):
         """Determine the changes required to apply the requested RAID config.
 
@@ -588,10 +601,11 @@ def _determine_required_changes(self, goal_vdisks):
                             create = False
 
             if create:
+                size_mb = self._compute_size_mb(goal_vdisk, min_size_mb)
                 create_vdisk = {
                     'physical_disks': goal_vdisk['pdisks'],
                     'raid_level': goal_vdisk['raid_level'],
-                    'size_mb': min_size_mb * goal_vdisk['span_depth'],
+                    'size_mb': size_mb,
                     'disk_name': goal_vdisk['name'],
                     'span_length': goal_vdisk['span_length'],
                     'span_depth': goal_vdisk['span_depth'],

tests/test_drac.py

@@ -1015,6 +1015,93 @@ def fake_resource_attr(elem, uri, attr):
              'span_length': 2, 'pending_operations': None,
              'physical_disks': ['pdisk3', 'pdisk4']})
 
+    def test_compute_size_mb(self):
+        goal_vdisk0 = {
+            'name': 'vdisk0',
+            'raid_level': 0,
+            'span_length': 1,
+            'span_depth': 2,
+            'pdisks': [
+                'pdisk1', 'pdisk2',
+            ],
+        }
+        self.assertEqual(
+            42 * 2, FakeRAIDConfig._compute_size_mb(goal_vdisk0, 42))
+
+        goal_vdisk1 = {
+            'name': 'vdisk1',
+            'raid_level': 1,
+            'span_length': 2,
+            'span_depth': 1,
+            'pdisks': [
+                'pdisk1', 'pdisk2',
+            ],
+        }
+        self.assertEqual(
+            42, FakeRAIDConfig._compute_size_mb(goal_vdisk1, 42))
+
+        goal_vdisk5 = {
+            'name': 'vdisk5',
+            'raid_level': 5,
+            'span_length': 3,
+            'span_depth': 1,
+            'pdisks': [
+                'pdisk1', 'pdisk2', 'pdisk3',
+            ],
+        }
+        self.assertEqual(
+            42 * 2, FakeRAIDConfig._compute_size_mb(goal_vdisk5, 42))
+
+        goal_vdisk6 = {
+            'name': 'vdisk6',
+            'raid_level': 6,
+            'span_length': 4,
+            'span_depth': 1,
+            'pdisks': [
+                'pdisk1', 'pdisk2', 'pdisk3', 'pdisk4',
+            ],
+        }
+        self.assertEqual(
+            42 * 2, FakeRAIDConfig._compute_size_mb(goal_vdisk6, 42))
+
+        goal_vdisk10 = {
+            'name': 'vdisk10',
+            'raid_level': '1+0',
+            'span_length': 2,
+            'span_depth': 3,
+            'pdisks': [
+                'pdisk1', 'pdisk2', 'pdisk3', 'pdisk4', 'pdisk5', 'pdisk6',
+            ],
+        }
+        self.assertEqual(
+            42 * 3, FakeRAIDConfig._compute_size_mb(goal_vdisk10, 42))
+
+        goal_vdisk50 = {
+            'name': 'vdisk50',
+            'raid_level': '5+0',
+            'span_length': 3,
+            'span_depth': 3,
+            'pdisks': [
+                'pdisk1', 'pdisk2', 'pdisk3', 'pdisk4', 'pdisk5', 'pdisk6',
+                'pdisk7', 'pdisk8', 'pdisk9',
+            ],
+        }
+        self.assertEqual(
+            42 * 2 * 3, FakeRAIDConfig._compute_size_mb(goal_vdisk50, 42))
+
+        goal_vdisk60 = {
+            'name': 'vdisk60',
+            'raid_level': '6+0',
+            'span_length': 4,
+            'span_depth': 2,
+            'pdisks': [
+                'pdisk1', 'pdisk2', 'pdisk3', 'pdisk4', 'pdisk5', 'pdisk6',
+                'pdisk7', 'pdisk8',
+            ],
+        }
+        self.assertEqual(
+            42 * 2 * 2, FakeRAIDConfig._compute_size_mb(goal_vdisk60, 42))
+
 
 class FakeBIOSConfig(drac.BIOSConfig):
     def __init__(self, state, changing_settings):