KVM and XEN Disk Management Parity

Implements blueprint disk-configuration-parity

This change splits local_gb into root_gb and ephemeral_gb. libvirt
interpreted local_gb as what ephemeral_gb is now, whereas XenAPI
interpreted local_gb as what root_gb is now.

Change-Id: I496600991bac1e990326d4ded1607fee08209d68

3 files changed, 18 insertions, 14 deletions

diff --git a/nova/compute/api.py b/nova/compute/api.py
index ca28f3871..a4c228e26 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -226,7 +226,7 @@ class API(base.Base):
 
         if instance_type['memory_mb'] < int(image.get('min_ram') or 0):
             raise exception.InstanceTypeMemoryTooSmall()
-        if instance_type['local_gb'] < int(image.get('min_disk') or 0):
+        if instance_type['root_gb'] < int(image.get('min_disk') or 0):
             raise exception.InstanceTypeDiskTooSmall()
 
         config_drive_id = None
@@ -315,7 +315,8 @@ class API(base.Base):
             'instance_type_id': instance_type['id'],
             'memory_mb': instance_type['memory_mb'],
             'vcpus': instance_type['vcpus'],
-            'local_gb': instance_type['local_gb'],
+            'root_gb': instance_type['root_gb'],
+            'ephemeral_gb': instance_type['ephemeral_gb'],
             'display_name': display_name,
             'display_description': display_description,
             'user_data': user_data or '',
@@ -376,13 +377,13 @@ class API(base.Base):
 
             # TODO(yamahata): ephemeralN where N > 0
             # Only ephemeral0 is allowed for now because InstanceTypes
-            # table only allows single local disk, local_gb.
+            # table only allows single local disk, ephemeral_gb.
             # In order to enhance it, we need to add a new columns to
             # instance_types table.
             if num > 0:
                 return 0
 
-            size = instance_type.get('local_gb')
+            size = instance_type.get('ephemeral_gb')
 
         return size
 
@@ -1240,7 +1241,7 @@ class API(base.Base):
         #disk format of vhd is non-shrinkable
         if orig_image.get('disk_format') == 'vhd':
             min_ram = instance['instance_type']['memory_mb']
-            min_disk = instance['instance_type']['local_gb']
+            min_disk = instance['instance_type']['root_gb']
         else:
             #set new image values to the original image values
             min_ram = orig_image.get('min_ram')
diff --git a/nova/compute/instance_types.py b/nova/compute/instance_types.py
index 58f479a07..191f9ca0e 100644
--- a/nova/compute/instance_types.py
+++ b/nova/compute/instance_types.py
@@ -30,13 +30,14 @@ FLAGS = flags.FLAGS
 LOG = logging.getLogger('nova.instance_types')
 
 
-def create(name, memory, vcpus, local_gb, flavorid, swap=0,
+def create(name, memory, vcpus, root_gb, ephemeral_gb, flavorid, swap=0,
            rxtx_factor=1):
     """Creates instance types."""
     kwargs = {
         'memory_mb': memory,
         'vcpus': vcpus,
-        'local_gb': local_gb,
+        'root_gb': root_gb,
+        'ephemeral_gb': ephemeral_gb,
         'swap': swap,
         'rxtx_factor': rxtx_factor,
     }
diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 65985ca02..f43c7a1a0 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -432,12 +432,12 @@ class ComputeManager(manager.SchedulerDependentManager):
 
         instance_type_id = instance['instance_type_id']
         instance_type = instance_types.get_instance_type(instance_type_id)
-        allowed_size_gb = instance_type['local_gb']
+        allowed_size_gb = instance_type['root_gb']
 
-        # NOTE(jk0): Since libvirt uses local_gb as a secondary drive, we
-        # need to handle potential situations where local_gb is 0. This is
-        # the default for m1.tiny.
-        if allowed_size_gb == 0:
+        # NOTE(johannes): root_gb is allowed to be 0 for legacy reasons
+        # since libvirt interpreted the value differently than other
+        # drivers. A value of 0 means don't check size.
+        if not allowed_size_gb:
             return image_meta
 
         allowed_size_bytes = allowed_size_gb * 1024 * 1024 * 1024
@@ -1111,7 +1111,8 @@ class ComputeManager(manager.SchedulerDependentManager):
                               memory_mb=instance_type['memory_mb'],
                               host=migration_ref['source_compute'],
                               vcpus=instance_type['vcpus'],
-                              local_gb=instance_type['local_gb'],
+                              root_gb=instance_type['root_gb'],
+                              ephemeral_gb=instance_type['ephemeral_gb'],
                               instance_type_id=instance_type['id'])
 
         self.driver.finish_revert_migration(instance_ref)
@@ -1238,7 +1239,8 @@ class ComputeManager(manager.SchedulerDependentManager):
                    dict(instance_type_id=instance_type['id'],
                         memory_mb=instance_type['memory_mb'],
                         vcpus=instance_type['vcpus'],
-                        local_gb=instance_type['local_gb']))
+                        root_gb=instance_type['root_gb'],
+                        ephemeral_gb=instance_type['ephemeral_gb']))
             resize_instance = True
 
         instance_ref = self.db.instance_get_by_uuid(context,