openstack/cinder
Code Issues Proposed changes

Over subscription for Pure Storage iSCSI driver.

Browse Source 
Add support for over subscription in Pure Storage iSCSI driver.

Implements: blueprint pure-iscsi-over-subscription-thin-provisioning
Change-Id: Ia9de828ad718c0790f4f04ee2a2f1eb4c3fe2788
This commit is contained in:
Daniel Wilson 2015-02-19 10:35:05 -08:00
parent 8bda008dd0
commit d469062417
2 changed files with 86 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
cinder/tests/test_pure.py
View File

@ -103,11 +103,16 @@ PORTS_WITHOUT = [NON_ISCSI_PORT]
VOLUME_CONNECTIONS = [{"host": "h1", "name": VOLUME["name"] + "-cinder"},
{"host": "h2", "name": VOLUME["name"] + "-cinder"},
]
TOTAL_SPACE = 50.0
FREE_SPACE = 32.1
SPACE_INFO = {"capacity": TOTAL_SPACE * units.Gi,
"total": (TOTAL_SPACE - FREE_SPACE) * units.Gi,
TOTAL_CAPACITY = 50.0
USED_SPACE = 32.1
PROVISIONED_CAPACITY = 70.0
DEFAULT_OVER_SUBSCRIPTION = 20
SPACE_INFO = {"capacity": TOTAL_CAPACITY * units.Gi,
"total": USED_SPACE * units.Gi
}
SPACE_INFO_EMPTY = {"capacity": TOTAL_CAPACITY * units.Gi,
"total": 0
}
class FakePureStorageHTTPError(Exception):
@ -570,17 +575,65 @@ class PureISCSIDriverTestCase(test.TestCase):
self.assertFalse(self.array.list_host_connections.called)
self.assertFalse(self.array.delete_host.called)
def test_get_volume_stats(self):
@mock.patch(DRIVER_OBJ + "._get_provisioned_space", autospec=True)
def test_get_volume_stats(self, mock_space):
mock_space.return_value = PROVISIONED_CAPACITY * units.Gi
self.assertEqual(self.driver.get_volume_stats(), {})
self.array.get.return_value = SPACE_INFO
result = {"volume_backend_name": VOLUME_BACKEND_NAME,
"vendor_name": "Pure Storage",
"driver_version": self.driver.VERSION,
"storage_protocol": "iSCSI",
"total_capacity_gb": TOTAL_SPACE,
"free_capacity_gb": FREE_SPACE,
"total_capacity_gb": TOTAL_CAPACITY,
"free_capacity_gb": TOTAL_CAPACITY - USED_SPACE,
"reserved_percentage": 0,
"consistencygroup_support": True
"consistencygroup_support": True,
"thin_provisioning_support": True,
"provisioned_capacity": PROVISIONED_CAPACITY,
"max_over_subscription_ratio": (PROVISIONED_CAPACITY /
USED_SPACE)
}
real_result = self.driver.get_volume_stats(refresh=True)
self.assertDictMatch(result, real_result)
self.assertDictMatch(result, self.driver._stats)
@mock.patch(DRIVER_OBJ + "._get_provisioned_space", autospec=True)
def test_get_volume_stats_empty_array(self, mock_space):
mock_space.return_value = PROVISIONED_CAPACITY * units.Gi
self.assertEqual(self.driver.get_volume_stats(), {})
self.array.get.return_value = SPACE_INFO_EMPTY
result = {"volume_backend_name": VOLUME_BACKEND_NAME,
"vendor_name": "Pure Storage",
"driver_version": self.driver.VERSION,
"storage_protocol": "iSCSI",
"total_capacity_gb": TOTAL_CAPACITY,
"free_capacity_gb": TOTAL_CAPACITY,
"reserved_percentage": 0,
"consistencygroup_support": True,
"thin_provisioning_support": True,
"provisioned_capacity": PROVISIONED_CAPACITY,
"max_over_subscription_ratio": DEFAULT_OVER_SUBSCRIPTION
}
real_result = self.driver.get_volume_stats(refresh=True)
self.assertDictMatch(result, real_result)
self.assertDictMatch(result, self.driver._stats)
@mock.patch(DRIVER_OBJ + "._get_provisioned_space", autospec=True)
def test_get_volume_stats_nothing_provisioned(self, mock_space):
mock_space.return_value = 0
self.assertEqual(self.driver.get_volume_stats(), {})
self.array.get.return_value = SPACE_INFO
result = {"volume_backend_name": VOLUME_BACKEND_NAME,
"vendor_name": "Pure Storage",
"driver_version": self.driver.VERSION,
"storage_protocol": "iSCSI",
"total_capacity_gb": TOTAL_CAPACITY,
"free_capacity_gb": TOTAL_CAPACITY - USED_SPACE,
"reserved_percentage": 0,
"consistencygroup_support": True,
"thin_provisioning_support": True,
"provisioned_capacity": 0,
"max_over_subscription_ratio": DEFAULT_OVER_SUBSCRIPTION
}
real_result = self.driver.get_volume_stats(refresh=True)
self.assertDictMatch(result, real_result)

31
cinder/volume/drivers/pure.py
View File

@ -99,7 +99,7 @@ def _generate_purity_host_name(name):
class PureISCSIDriver(san.SanISCSIDriver):
"""Performs volume management on Pure Storage FlashArray."""
VERSION = "2.0.3"
VERSION = "2.0.4"
SUPPORTED_REST_API_VERSIONS = ['1.2', '1.3', '1.4']
@ -382,19 +382,38 @@ class PureISCSIDriver(san.SanISCSIDriver):
def _update_stats(self):
"""Set self._stats with relevant information."""
info = self._array.get(space=True)
total = float(info["capacity"]) / units.Gi
free = float(info["capacity"] - info["total"]) / units.Gi
total_capacity = float(info["capacity"]) / units.Gi
used_space = float(info["total"]) / units.Gi
free_space = float(total_capacity - used_space)
provisioned_space = float(self._get_provisioned_space()) / units.Gi
# If array is empty we can not calculate a max oversubscription ratio.
# In this case we choose 20 as a default value for the ratio. Once
# some volumes are actually created and some data is stored on the
# array a much more accurate number will be presented based on current
# usage.
if used_space == 0 or provisioned_space == 0:
thin_provisioning = 20
else:
thin_provisioning = provisioned_space / used_space
data = {"volume_backend_name": self._backend_name,
"vendor_name": "Pure Storage",
"driver_version": self.VERSION,
"storage_protocol": "iSCSI",
"total_capacity_gb": total,
"free_capacity_gb": free,
"total_capacity_gb": total_capacity,
"free_capacity_gb": free_space,
"reserved_percentage": 0,
"consistencygroup_support": True
"consistencygroup_support": True,
"thin_provisioning_support": True,
"provisioned_capacity": provisioned_space,
"max_over_subscription_ratio": thin_provisioning
}
self._stats = data
def _get_provisioned_space(self):
"""Sum up provisioned size of all volumes on array"""
volumes = self._array.list_volumes(pending=True)
return sum(item["size"] for item in volumes)
def extend_volume(self, volume, new_size):
"""Extend volume to new_size."""
LOG.debug("Enter PureISCSIDriver.extend_volume.")