diff --git a/cinder/common/constants.py b/cinder/common/constants.py
index 61c84132d74..d8030333070 100644
--- a/cinder/common/constants.py
+++ b/cinder/common/constants.py
@@ -29,3 +29,33 @@ LOG_BINARIES = (SCHEDULER_BINARY, VOLUME_BINARY, BACKUP_BINARY, API_BINARY)
 
 # The encryption key ID used by the legacy fixed-key ConfKeyMgr
 FIXED_KEY_ID = '00000000-0000-0000-0000-000000000000'
+
+# Storage protocol constants
+CEPH = 'ceph'
+DRBD = 'DRBD'
+FC = 'FC'
+FC_VARIANT_1 = 'fibre_channel'
+FC_VARIANT_2 = 'fc'
+FILE = 'file'
+ISCSI = 'iSCSI'
+ISCSI_VARIANT = 'iscsi'
+ISER = 'iSER'
+LIGHTOS = 'lightos'
+NFS = 'NFS'
+NFS_VARIANT = 'nfs'
+NVMEOF = 'NVMe-oF'
+NVMEOF_VARIANT_1 = 'NVMeOF'
+NVMEOF_VARIANT_2 = 'nvmeof'
+SCALEIO = 'scaleio'
+SCSI = 'SCSI'
+STORPOOL = 'storpool'
+VMDK = 'vmdk'
+VSTORAGE = 'vstorageobject'
+
+# These must be strings, because there are places that check specific type
+ISCSI_VARIANTS = [ISCSI, ISCSI_VARIANT]
+FC_VARIANTS = [FC, FC_VARIANT_1, FC_VARIANT_2]
+NFS_VARIANTS = [NFS, NFS_VARIANT]
+NVMEOF_VARIANTS = [NVMEOF, NVMEOF_VARIANT_1, NVMEOF_VARIANT_2]
+
+CACHEABLE_PROTOCOLS = FC_VARIANTS + ISCSI_VARIANTS + NVMEOF_VARIANTS
diff --git a/cinder/volume/driver.py b/cinder/volume/driver.py
index 69d6b22d01c..5f097f19a8e 100644
--- a/cinder/volume/driver.py
+++ b/cinder/volume/driver.py
@@ -25,6 +25,7 @@ from oslo_config import types
 from oslo_log import log as logging
 from oslo_utils import excutils
 
+from cinder.common import constants
 from cinder import db
 from cinder import exception
 from cinder.i18n import _
@@ -221,8 +222,8 @@ volume_opts = [
                      'directly, it will only notify that it can be used.'),
     cfg.StrOpt('storage_protocol',
                ignore_case=True,
-               default='iscsi',
-               choices=['iscsi', 'fc'],
+               default=constants.ISCSI,
+               choices=[constants.ISCSI, constants.FC],
                help='Protocol for transferring data between host and '
                     'storage back-end.'),
     cfg.BoolOpt('enable_unsupported_driver',
@@ -2805,7 +2806,7 @@ class ISCSIDriver(VolumeDriver):
         data["volume_backend_name"] = backend_name or 'Generic_iSCSI'
         data["vendor_name"] = 'Open Source'
         data["driver_version"] = '1.0'
-        data["storage_protocol"] = 'iSCSI'
+        data["storage_protocol"] = constants.ISCSI
         data["pools"] = []
         data["replication_enabled"] = False
 
@@ -2874,7 +2875,7 @@ class ISERDriver(ISCSIDriver):
         data["volume_backend_name"] = backend_name or 'Generic_iSER'
         data["vendor_name"] = 'Open Source'
         data["driver_version"] = '1.0'
-        data["storage_protocol"] = 'iSER'
+        data["storage_protocol"] = constants.ISER
         data["pools"] = []
 
         self._update_pools_and_stats(data)
@@ -2950,7 +2951,7 @@ class FibreChannelDriver(VolumeDriver):
         data["volume_backend_name"] = backend_name or 'Generic_FC'
         data["vendor_name"] = 'Open Source'
         data["driver_version"] = '1.0'
-        data["storage_protocol"] = 'FC'
+        data["storage_protocol"] = constants.FC
         data["pools"] = []
 
         self._update_pools_and_stats(data)
diff --git a/cinder/volume/drivers/ceph/rbd_iscsi.py b/cinder/volume/drivers/ceph/rbd_iscsi.py
index 8ec821493e6..42aa3c65fea 100644
--- a/cinder/volume/drivers/ceph/rbd_iscsi.py
+++ b/cinder/volume/drivers/ceph/rbd_iscsi.py
@@ -17,6 +17,7 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import netutils
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -72,7 +73,7 @@ class RBDISCSIDriver(rbd.RBDDriver):
 
     SUPPORTS_ACTIVE_ACTIVE = True
 
-    STORAGE_PROTOCOL = 'iSCSI'
+    STORAGE_PROTOCOL = constants.ISCSI
     CHAP_LENGTH = 16
 
     # The target IQN to use for creating all exports
diff --git a/cinder/volume/drivers/datera/datera_api21.py b/cinder/volume/drivers/datera/datera_api21.py
index 2379f3606c5..69d161e8729 100644
--- a/cinder/volume/drivers/datera/datera_api21.py
+++ b/cinder/volume/drivers/datera/datera_api21.py
@@ -28,6 +28,7 @@ from oslo_utils import importutils
 from oslo_utils import units
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.image import image_utils
@@ -975,7 +976,7 @@ class DateraApi(object):
                     'volume_backend_name': self.backend_name,
                     'vendor_name': 'Datera',
                     'driver_version': self.VERSION,
-                    'storage_protocol': 'iSCSI',
+                    'storage_protocol': constants.ISCSI,
                     'total_capacity_gb': (
                         int(results.total_capacity) / units.Gi),
                     'free_capacity_gb': (
diff --git a/cinder/volume/drivers/datera/datera_api22.py b/cinder/volume/drivers/datera/datera_api22.py
index 4dab3d9b798..1fa26c6660d 100644
--- a/cinder/volume/drivers/datera/datera_api22.py
+++ b/cinder/volume/drivers/datera/datera_api22.py
@@ -28,6 +28,7 @@ from oslo_utils import importutils
 from oslo_utils import units
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.image import image_utils
@@ -1026,7 +1027,7 @@ class DateraApi(object):
                     'volume_backend_name': self.backend_name,
                     'vendor_name': 'Datera',
                     'driver_version': self.VERSION,
-                    'storage_protocol': 'iSCSI',
+                    'storage_protocol': constants.ISCSI,
                     'total_capacity_gb': (
                         int(results.total_capacity) / units.Gi),
                     'free_capacity_gb': (
diff --git a/cinder/volume/drivers/dell_emc/powerflex/driver.py b/cinder/volume/drivers/dell_emc/powerflex/driver.py
index 7989af24658..0ac24fd50f5 100644
--- a/cinder/volume/drivers/dell_emc/powerflex/driver.py
+++ b/cinder/volume/drivers/dell_emc/powerflex/driver.py
@@ -29,6 +29,7 @@ from oslo_utils import units
 import six
 from six.moves import http_client
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -956,7 +957,7 @@ class PowerFlexDriver(driver.VolumeDriver):
         stats["volume_backend_name"] = backend_name or "powerflex"
         stats["vendor_name"] = "Dell EMC"
         stats["driver_version"] = self.VERSION
-        stats["storage_protocol"] = "scaleio"
+        stats["storage_protocol"] = constants.SCALEIO
         stats["reserved_percentage"] = 0
         stats["QoS_support"] = True
         stats["consistent_group_snapshot_enabled"] = True
diff --git a/cinder/volume/drivers/dell_emc/powermax/fc.py b/cinder/volume/drivers/dell_emc/powermax/fc.py
index f477bd3e066..2a2824a365b 100644
--- a/cinder/volume/drivers/dell_emc/powermax/fc.py
+++ b/cinder/volume/drivers/dell_emc/powermax/fc.py
@@ -17,6 +17,7 @@ import ast
 
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder import interface
 from cinder.volume import driver
@@ -538,7 +539,7 @@ class PowerMaxFCDriver(san.SanDriver, driver.FibreChannelDriver):
         """Retrieve stats info from volume group."""
         LOG.debug("Updating volume stats")
         data = self.common.update_volume_stats()
-        data['storage_protocol'] = 'FC'
+        data['storage_protocol'] = constants.FC
         data['driver_version'] = self.VERSION
         self._stats = data
 
diff --git a/cinder/volume/drivers/dell_emc/powermax/iscsi.py b/cinder/volume/drivers/dell_emc/powermax/iscsi.py
index 21e9ab537db..c87f05d19cd 100644
--- a/cinder/volume/drivers/dell_emc/powermax/iscsi.py
+++ b/cinder/volume/drivers/dell_emc/powermax/iscsi.py
@@ -22,6 +22,7 @@ from oslo_log import log as logging
 from oslo_utils import strutils
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -452,7 +453,7 @@ class PowerMaxISCSIDriver(san.SanISCSIDriver):
         """Retrieve stats info from volume group."""
         LOG.debug("Updating volume stats")
         data = self.common.update_volume_stats()
-        data['storage_protocol'] = 'iSCSI'
+        data['storage_protocol'] = constants.ISCSI
         data['driver_version'] = self.VERSION
         self._stats = data
 
diff --git a/cinder/volume/drivers/dell_emc/powerstore/adapter.py b/cinder/volume/drivers/dell_emc/powerstore/adapter.py
index 343e12a2ea3..2154a106b9c 100644
--- a/cinder/volume/drivers/dell_emc/powerstore/adapter.py
+++ b/cinder/volume/drivers/dell_emc/powerstore/adapter.py
@@ -18,6 +18,7 @@
 from oslo_log import log as logging
 from oslo_utils import strutils
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -31,8 +32,8 @@ from cinder.volume import volume_utils
 
 
 LOG = logging.getLogger(__name__)
-PROTOCOL_FC = "FC"
-PROTOCOL_ISCSI = "iSCSI"
+PROTOCOL_FC = constants.FC
+PROTOCOL_ISCSI = constants.ISCSI
 CHAP_MODE_SINGLE = "Single"
 
 
diff --git a/cinder/volume/drivers/dell_emc/sc/storagecenter_api.py b/cinder/volume/drivers/dell_emc/sc/storagecenter_api.py
index 7c08a99d942..1d7ab1d8d62 100644
--- a/cinder/volume/drivers/dell_emc/sc/storagecenter_api.py
+++ b/cinder/volume/drivers/dell_emc/sc/storagecenter_api.py
@@ -24,6 +24,7 @@ import requests
 import six
 from six.moves import http_client
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import utils
@@ -373,7 +374,7 @@ class SCApiHelper(object):
                                               connection.excluded_domain_ips))
         # Our primary SSN doesn't change
         connection.primaryssn = self.primaryssn
-        if self.storage_protocol == 'FC':
+        if self.storage_protocol == constants.FC:
             connection.protocol = 'FibreChannel'
         # Set appropriate ssn and failover state.
         if self.active_backend_id:
diff --git a/cinder/volume/drivers/dell_emc/sc/storagecenter_common.py b/cinder/volume/drivers/dell_emc/sc/storagecenter_common.py
index 5e78ef4e390..67ce942ad36 100644
--- a/cinder/volume/drivers/dell_emc/sc/storagecenter_common.py
+++ b/cinder/volume/drivers/dell_emc/sc/storagecenter_common.py
@@ -19,6 +19,7 @@ from oslo_log import log as logging
 from oslo_utils import excutils
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.objects import fields
@@ -112,7 +113,7 @@ class SCCommonDriver(driver.ManageableVD,
         LOG.info('Loading %(name)s: Failover state is %(state)r',
                  {'name': self.backend_name,
                   'state': self.failed_over})
-        self.storage_protocol = 'iSCSI'
+        self.storage_protocol = constants.ISCSI
         self.failback_timeout = 60
 
     @staticmethod
diff --git a/cinder/volume/drivers/dell_emc/sc/storagecenter_fc.py b/cinder/volume/drivers/dell_emc/sc/storagecenter_fc.py
index 377edfc8233..636a56b9094 100644
--- a/cinder/volume/drivers/dell_emc/sc/storagecenter_fc.py
+++ b/cinder/volume/drivers/dell_emc/sc/storagecenter_fc.py
@@ -17,6 +17,7 @@
 from oslo_log import log as logging
 from oslo_utils import excutils
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -77,7 +78,7 @@ class SCFCDriver(storagecenter_common.SCCommonDriver,
         super(SCFCDriver, self).__init__(*args, **kwargs)
         self.backend_name =\
             self.configuration.safe_get('volume_backend_name') or 'Dell-FC'
-        self.storage_protocol = 'FC'
+        self.storage_protocol = constants.FC
 
     def validate_connector(self, connector):
         """Fail if connector doesn't contain all the data needed by driver.
diff --git a/cinder/volume/drivers/dell_emc/unity/adapter.py b/cinder/volume/drivers/dell_emc/unity/adapter.py
index 93a8eb7d95f..6ee99fbb420 100644
--- a/cinder/volume/drivers/dell_emc/unity/adapter.py
+++ b/cinder/volume/drivers/dell_emc/unity/adapter.py
@@ -24,6 +24,7 @@ from oslo_log import log as logging
 from oslo_utils import excutils
 from oslo_utils import importutils
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.objects import fields
@@ -44,8 +45,8 @@ else:
 
 LOG = logging.getLogger(__name__)
 
-PROTOCOL_FC = 'FC'
-PROTOCOL_ISCSI = 'iSCSI'
+PROTOCOL_FC = constants.FC
+PROTOCOL_ISCSI = constants.ISCSI
 
 
 class VolumeParams(object):
diff --git a/cinder/volume/drivers/dell_emc/xtremio.py b/cinder/volume/drivers/dell_emc/xtremio.py
index 53847a7a6c9..567096e495d 100644
--- a/cinder/volume/drivers/dell_emc/xtremio.py
+++ b/cinder/volume/drivers/dell_emc/xtremio.py
@@ -49,6 +49,7 @@ import requests
 import six
 from six.moves import http_client
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -1101,7 +1102,7 @@ class XtremIOISCSIDriver(XtremIOVolumeDriver, driver.ISCSIDriver):
 
     def __init__(self, *args, **kwargs):
         super(XtremIOISCSIDriver, self).__init__(*args, **kwargs)
-        self.protocol = 'iSCSI'
+        self.protocol = constants.ISCSI
 
     def _add_auth(self, data, login_chap, discovery_chap):
         login_passwd, discovery_passwd = None, None
@@ -1240,7 +1241,7 @@ class XtremIOFCDriver(XtremIOVolumeDriver,
 
     def __init__(self, *args, **kwargs):
         super(XtremIOFCDriver, self).__init__(*args, **kwargs)
-        self.protocol = 'FC'
+        self.protocol = constants.FC
         self._targets = None
 
     def get_targets(self):
diff --git a/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_fc.py b/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_fc.py
index b5c8bf398cd..550ae38e1da 100644
--- a/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_fc.py
+++ b/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_fc.py
@@ -22,6 +22,7 @@ FibreChannel Cinder Volume driver for Fujitsu ETERNUS DX S3 series.
 from oslo_log import log as logging
 import six
 
+from cinder.common import constants
 from cinder import interface
 from cinder.volume import driver
 from cinder.volume.drivers.fujitsu.eternus_dx import eternus_dx_common
@@ -202,7 +203,7 @@ class FJDXFCDriver(driver.FibreChannelDriver):
             data, pool_name = self.common.update_volume_stats()
             backend_name = self.configuration.safe_get('volume_backend_name')
             data['volume_backend_name'] = backend_name or 'FJDXFCDriver'
-            data['storage_protocol'] = 'FC'
+            data['storage_protocol'] = constants.FC
             self._stats = data
 
         LOG.debug('get_volume_stats, '
diff --git a/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_iscsi.py b/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_iscsi.py
index a158a7e98ae..f3d7fdd58d5 100644
--- a/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_iscsi.py
+++ b/cinder/volume/drivers/fujitsu/eternus_dx/eternus_dx_iscsi.py
@@ -20,6 +20,7 @@
 from oslo_log import log as logging
 import six
 
+from cinder.common import constants
 from cinder import interface
 from cinder.volume import driver
 from cinder.volume.drivers.fujitsu.eternus_dx import eternus_dx_common
@@ -192,7 +193,7 @@ class FJDXISCSIDriver(driver.ISCSIDriver):
             data, pool_name = self.common.update_volume_stats()
             backend_name = self.configuration.safe_get('volume_backend_name')
             data['volume_backend_name'] = backend_name or 'FJDXISCSIDriver'
-            data['storage_protocol'] = 'iSCSI'
+            data['storage_protocol'] = constants.ISCSI
             self._stats = data
 
         LOG.debug('get_volume_stats, '
diff --git a/cinder/volume/drivers/fusionstorage/dsware.py b/cinder/volume/drivers/fusionstorage/dsware.py
index 91a2d9cf8cb..43b4eac85b9 100644
--- a/cinder/volume/drivers/fusionstorage/dsware.py
+++ b/cinder/volume/drivers/fusionstorage/dsware.py
@@ -19,6 +19,7 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import units
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -159,7 +160,7 @@ class DSWAREDriver(driver.VolumeDriver):
                 "thin_provisioning_support": False,
                 "pools": [],
                 "vendor_name": "Huawei",
-                "storage_protocol": "SCSI",
+                "storage_protocol": constants.SCSI,
                 }
         all_pools = self.client.query_pool_info()
 
diff --git a/cinder/volume/drivers/hedvig/hedvig_cinder.py b/cinder/volume/drivers/hedvig/hedvig_cinder.py
index f7cc9756d41..58a4b0a83b7 100644
--- a/cinder/volume/drivers/hedvig/hedvig_cinder.py
+++ b/cinder/volume/drivers/hedvig/hedvig_cinder.py
@@ -24,6 +24,7 @@ from oslo_log import log as logging
 from oslo_utils import strutils
 from oslo_utils import units
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -97,7 +98,7 @@ class HedvigISCSIDriver(driver.ISCSIDriver, san.SanDriver):
             stats["volume_backend_name"] = "hedvig"
             stats["vendor_name"] = "Hedvig Inc"
             stats["driver_version"] = self.VERSION
-            stats["storage_protocol"] = "iSCSI"
+            stats["storage_protocol"] = constants.ISCSI
             stats["total_capacity_gb"] = total_capacity
             stats["free_capacity_gb"] = free_capacity
             stats["QoS_support"] = True
diff --git a/cinder/volume/drivers/hpe/hpe_3par_fc.py b/cinder/volume/drivers/hpe/hpe_3par_fc.py
index 4fd702492e2..e0874dd4b2e 100644
--- a/cinder/volume/drivers/hpe/hpe_3par_fc.py
+++ b/cinder/volume/drivers/hpe/hpe_3par_fc.py
@@ -37,6 +37,7 @@ except ImportError:
 from oslo_log import log as logging
 from oslo_utils.excutils import save_and_reraise_exception
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import interface
 from cinder.volume.drivers.hpe import hpe_3par_base as hpebasedriver
@@ -125,7 +126,7 @@ class HPE3PARFCDriver(hpebasedriver.HPE3PARDriverBase):
     def __init__(self, *args, **kwargs):
         super(HPE3PARFCDriver, self).__init__(*args, **kwargs)
         self.lookup_service = fczm_utils.create_lookup_service()
-        self.protocol = 'FC'
+        self.protocol = constants.FC
 
     def _initialize_connection_common(self, volume, connector, common, host,
                                       target_wwns, init_targ_map, numPaths,
diff --git a/cinder/volume/drivers/hpe/hpe_3par_iscsi.py b/cinder/volume/drivers/hpe/hpe_3par_iscsi.py
index ab851868d9c..2d949840e32 100644
--- a/cinder/volume/drivers/hpe/hpe_3par_iscsi.py
+++ b/cinder/volume/drivers/hpe/hpe_3par_iscsi.py
@@ -38,6 +38,7 @@ except ImportError:
 from oslo_log import log as logging
 from oslo_utils.excutils import save_and_reraise_exception
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -138,7 +139,7 @@ class HPE3PARISCSIDriver(hpebasedriver.HPE3PARDriverBase):
 
     def __init__(self, *args, **kwargs):
         super(HPE3PARISCSIDriver, self).__init__(*args, **kwargs)
-        self.protocol = 'iSCSI'
+        self.protocol = constants.ISCSI
 
     def _do_setup(self, common):
         client_obj = common.client
diff --git a/cinder/volume/drivers/hpe/nimble.py b/cinder/volume/drivers/hpe/nimble.py
index cbabc58f9b7..f061176c0e2 100644
--- a/cinder/volume/drivers/hpe/nimble.py
+++ b/cinder/volume/drivers/hpe/nimble.py
@@ -34,6 +34,7 @@ from oslo_utils import units
 import requests
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -586,7 +587,7 @@ class NimbleBaseVolumeDriver(san.SanDriver):
                 password=self.configuration.san_password,
                 ip=self.configuration.san_ip,
                 verify=self.verify)
-            if self._storage_protocol == "iSCSI":
+            if self._storage_protocol == constants.ISCSI:
                 group_info = self.APIExecutor.get_group_info()
                 self._enable_group_scoped_target(group_info)
         except Exception:
@@ -670,10 +671,10 @@ class NimbleBaseVolumeDriver(san.SanDriver):
         LOG.info('Creating initiator group %(grp)s '
                  'with initiator %(iname)s',
                  {'grp': igrp_name, 'iname': initiator_name})
-        if self._storage_protocol == "iSCSI":
+        if self._storage_protocol == constants.ISCSI:
             self.APIExecutor.create_initiator_group(igrp_name)
             self.APIExecutor.add_initiator_to_igroup(igrp_name, initiator_name)
-        elif self._storage_protocol == "FC":
+        elif self._storage_protocol == constants.FC:
             self.APIExecutor.create_initiator_group_fc(igrp_name)
             for wwpn in wwpns:
                 self.APIExecutor.add_initiator_to_igroup_fc(igrp_name, wwpn)
@@ -952,7 +953,7 @@ class NimbleISCSIDriver(NimbleBaseVolumeDriver, san.SanISCSIDriver):
 
     def __init__(self, *args, **kwargs):
         super(NimbleISCSIDriver, self).__init__(*args, **kwargs)
-        self._storage_protocol = "iSCSI"
+        self._storage_protocol = constants.ISCSI
         self._group_target_name = None
 
     def _set_gst_for_group(self):
@@ -1126,7 +1127,7 @@ class NimbleFCDriver(NimbleBaseVolumeDriver, driver.FibreChannelDriver):
 
     def __init__(self, *args, **kwargs):
         super(NimbleFCDriver, self).__init__(*args, **kwargs)
-        self._storage_protocol = "FC"
+        self._storage_protocol = constants.FC
         self._lookup_service = fczm_utils.create_lookup_service()
 
     def _get_provider_location(self, volume_name):
@@ -1545,7 +1546,7 @@ class NimbleRestAPIExecutor(object):
                  'perfpolicy_id': perf_policy_id,
                  'encryption_cipher': cipher}}
 
-        if protocol == "iSCSI":
+        if protocol == constants.ISCSI:
             data['data']['multi_initiator'] = multi_initiator
 
         if dedupe.lower() == 'true':
@@ -2012,7 +2013,7 @@ class NimbleRestAPIExecutor(object):
                          "encryption_cipher": cipher
                          }
                 }
-        if protocol == "iSCSI":
+        if protocol == constants.ISCSI:
             data['data']['multi_initiator'] = multi_initiator
 
         folder_id = None
diff --git a/cinder/volume/drivers/huawei/huawei_driver.py b/cinder/volume/drivers/huawei/huawei_driver.py
index 1095cf0d73b..0312ba34828 100644
--- a/cinder/volume/drivers/huawei/huawei_driver.py
+++ b/cinder/volume/drivers/huawei/huawei_driver.py
@@ -18,6 +18,7 @@ import json
 from oslo_log import log as logging
 from oslo_utils import strutils
 
+from cinder.common import constants as cinder_constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -72,7 +73,7 @@ class HuaweiISCSIDriver(common.HuaweiBaseDriver, driver.ISCSIDriver):
     def get_volume_stats(self, refresh=False):
         """Get volume status."""
         data = self._get_volume_stats(refresh=False)
-        data['storage_protocol'] = 'iSCSI'
+        data['storage_protocol'] = cinder_constants.ISCSI
         data['driver_version'] = self.VERSION
         return data
 
@@ -264,7 +265,7 @@ class HuaweiFCDriver(common.HuaweiBaseDriver, driver.FibreChannelDriver):
     def get_volume_stats(self, refresh=False):
         """Get volume status."""
         data = self._get_volume_stats(refresh=False)
-        data['storage_protocol'] = 'FC'
+        data['storage_protocol'] = cinder_constants.FC
         data['driver_version'] = self.VERSION
         return data
 
diff --git a/cinder/volume/drivers/ibm/gpfs.py b/cinder/volume/drivers/ibm/gpfs.py
index aa9ea89ebe5..892e7ce384b 100644
--- a/cinder/volume/drivers/ibm/gpfs.py
+++ b/cinder/volume/drivers/ibm/gpfs.py
@@ -28,6 +28,7 @@ from oslo_utils import units
 import paramiko
 import six
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -856,7 +857,7 @@ class GPFSDriver(driver.CloneableImageVD,
         data["volume_backend_name"] = backend_name or 'GPFS'
         data["vendor_name"] = 'IBM'
         data["driver_version"] = self.VERSION
-        data["storage_protocol"] = 'file'
+        data["storage_protocol"] = constants.FILE
         free, capacity = self._get_available_capacity(self.configuration.
                                                       gpfs_mount_point_base)
         data['total_capacity_gb'] = math.ceil(capacity / units.Gi)
@@ -1561,7 +1562,7 @@ class GPFSNFSDriver(GPFSDriver, nfs.NfsDriver, san.SanDriver):
         data['volume_backend_name'] = backend_name or 'GPFSNFS'
         data['vendor_name'] = 'IBM'
         data['driver_version'] = self.get_version()
-        data['storage_protocol'] = 'file'
+        data['storage_protocol'] = constants.FILE
 
         self._ensure_shares_mounted()
 
diff --git a/cinder/volume/drivers/ibm/storwize_svc/storwize_svc_iscsi.py b/cinder/volume/drivers/ibm/storwize_svc/storwize_svc_iscsi.py
index 9e4d9211f60..041a5f6276d 100644
--- a/cinder/volume/drivers/ibm/storwize_svc/storwize_svc_iscsi.py
+++ b/cinder/volume/drivers/ibm/storwize_svc/storwize_svc_iscsi.py
@@ -39,6 +39,7 @@ from oslo_log import log as logging
 from oslo_utils import excutils
 from oslo_utils import strutils
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -104,7 +105,7 @@ class StorwizeSVCISCSIDriver(storwize_common.StorwizeSVCCommonDriver):
 
     def __init__(self, *args, **kwargs):
         super(StorwizeSVCISCSIDriver, self).__init__(*args, **kwargs)
-        self.protocol = 'iSCSI'
+        self.protocol = constants.ISCSI
         self.configuration.append_config_values(
             storwize_svc_iscsi_opts)
 
diff --git a/cinder/volume/drivers/infinidat.py b/cinder/volume/drivers/infinidat.py
index f9a7853196a..0dae912b1b7 100644
--- a/cinder/volume/drivers/infinidat.py
+++ b/cinder/volume/drivers/infinidat.py
@@ -24,6 +24,7 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import units
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -164,12 +165,12 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
         self._backend_name = backend_name or self.__class__.__name__
         self._volume_stats = None
         if self.configuration.infinidat_storage_protocol.lower() == 'iscsi':
-            self._protocol = 'iSCSI'
+            self._protocol = constants.ISCSI
             if len(self.configuration.infinidat_iscsi_netspaces) == 0:
                 msg = _('No iSCSI network spaces configured')
                 raise exception.VolumeDriverException(message=msg)
         else:
-            self._protocol = 'FC'
+            self._protocol = constants.FC
         if (self.configuration.infinidat_use_compression and
            not self._system.compat.has_compression()):
             # InfiniBox systems support compression only from v3.0 and up
@@ -182,7 +183,8 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
         LOG.debug('setup complete')
 
     def validate_connector(self, connector):
-        required = 'initiator' if self._protocol == 'iSCSI' else 'wwpns'
+        required = ('initiator' if self._protocol == constants.ISCSI
+                    else 'wwpns')
         if required not in connector:
             LOG.error('The volume driver requires %(data)s '
                       'in the connector.', {'data': required})
@@ -419,7 +421,7 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
         if connector is None:
             # If no connector was provided it is a force-detach - remove all
             # host connections for the volume
-            if self._protocol == 'FC':
+            if self._protocol == constants.FC:
                 port_cls = wwn.WWN
             else:
                 port_cls = iqn.IQN
@@ -429,7 +431,7 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
                 host_ports = [port for port in host_ports
                               if isinstance(port, port_cls)]
                 ports.extend(host_ports)
-        elif self._protocol == 'FC':
+        elif self._protocol == constants.FC:
             ports = [wwn.WWN(wwpn) for wwpn in connector['wwpns']]
         else:
             ports = [iqn.IQN(connector['initiator'])]
@@ -439,7 +441,7 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
     @coordination.synchronized('infinidat-{self.management_address}-lock')
     def initialize_connection(self, volume, connector):
         """Map an InfiniBox volume to the host"""
-        if self._protocol == 'FC':
+        if self._protocol == constants.FC:
             return self._initialize_connection_fc(volume, connector)
         else:
             return self._initialize_connection_iscsi(volume, connector)
@@ -449,7 +451,7 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
     def terminate_connection(self, volume, connector, **kwargs):
         """Unmap an InfiniBox volume from the host"""
         infinidat_volume = self._get_infinidat_volume(volume)
-        if self._protocol == 'FC':
+        if self._protocol == constants.FC:
             volume_type = 'fibre_channel'
         else:
             volume_type = 'iscsi'
@@ -469,7 +471,7 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
             # check if the host now doesn't have mappings
             if host is not None and len(host.get_luns()) == 0:
                 host.safe_delete()
-                if self._protocol == 'FC' and connector is not None:
+                if self._protocol == constants.FC and connector is not None:
                     # Create initiator-target mapping to delete host entry
                     # this is only relevant for regular (specific host) detach
                     target_wwpns = list(self._get_online_fc_ports())
@@ -480,7 +482,7 @@ class InfiniboxVolumeDriver(san.SanISCSIDriver):
                                        initiator_target_map=target_map)
         conn_info = dict(driver_volume_type=volume_type,
                          data=result_data)
-        if self._protocol == 'FC':
+        if self._protocol == constants.FC:
             fczm_utils.remove_fc_zone(conn_info)
         return conn_info
 
diff --git a/cinder/volume/drivers/inspur/as13000/as13000_driver.py b/cinder/volume/drivers/inspur/as13000/as13000_driver.py
index 59ca8ddec08..70e85d629af 100644
--- a/cinder/volume/drivers/inspur/as13000/as13000_driver.py
+++ b/cinder/volume/drivers/inspur/as13000/as13000_driver.py
@@ -29,6 +29,7 @@ from oslo_log import log as logging
 from oslo_utils import units
 import requests
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -176,7 +177,6 @@ class AS13000Driver(san.SanISCSIDriver):
 
     VENDOR = 'INSPUR'
     VERSION = '1.0.0'
-    PROTOCOL = 'iSCSI'
 
     # ThirdPartySystems wiki page
     CI_WIKI_NAME = 'Inspur_CI'
@@ -474,7 +474,7 @@ class AS13000Driver(san.SanISCSIDriver):
         backend_name = self.configuration.safe_get('volume_backend_name')
         data['vendor_name'] = self.VENDOR
         data['driver_version'] = self.VERSION
-        data['storage_protocol'] = self.PROTOCOL
+        data['storage_protocol'] = constants.ISCSI
         data['volume_backend_name'] = backend_name
         data['pools'] = self._get_pools_stats()
 
diff --git a/cinder/volume/drivers/inspur/instorage/instorage_common.py b/cinder/volume/drivers/inspur/instorage/instorage_common.py
index 4945ab68e65..66b9953cc52 100644
--- a/cinder/volume/drivers/inspur/instorage/instorage_common.py
+++ b/cinder/volume/drivers/inspur/instorage/instorage_common.py
@@ -32,6 +32,7 @@ from oslo_utils import units
 import paramiko
 import six
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -212,11 +213,11 @@ class InStorageMCSCommonDriver(driver.VolumeDriver, san.SanDriver):
         for k, node in self._state['storage_nodes'].items():
             if ((len(node['ipv4']) or len(node['ipv6'])) and
                     len(node['iscsi_name'])):
-                node['enabled_protocols'].append('iSCSI')
-                self._state['enabled_protocols'].add('iSCSI')
+                node['enabled_protocols'].append(constants.ISCSI)
+                self._state['enabled_protocols'].add(constants.ISCSI)
             if len(node['WWPN']):
-                node['enabled_protocols'].append('FC')
-                self._state['enabled_protocols'].add('FC')
+                node['enabled_protocols'].append(constants.FC)
+                self._state['enabled_protocols'].add(constants.FC)
             if not len(node['enabled_protocols']):
                 to_delete.append(k)
         for delkey in to_delete:
diff --git a/cinder/volume/drivers/kaminario/kaminario_fc.py b/cinder/volume/drivers/kaminario/kaminario_fc.py
index f1db77db2cb..c00ae1490fb 100644
--- a/cinder/volume/drivers/kaminario/kaminario_fc.py
+++ b/cinder/volume/drivers/kaminario/kaminario_fc.py
@@ -15,6 +15,7 @@
 """Volume driver for Kaminario K2 all-flash arrays."""
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import coordination
 from cinder.i18n import _
 from cinder.objects import fields
@@ -45,7 +46,7 @@ class KaminarioFCDriver(common.KaminarioCinderDriver):
     @volume_utils.trace
     def __init__(self, *args, **kwargs):
         super(KaminarioFCDriver, self).__init__(*args, **kwargs)
-        self._protocol = 'FC'
+        self._protocol = constants.FC
         self.lookup_service = fczm_utils.create_lookup_service()
 
     @volume_utils.trace
diff --git a/cinder/volume/drivers/kaminario/kaminario_iscsi.py b/cinder/volume/drivers/kaminario/kaminario_iscsi.py
index 5d97c3ce104..c93abccee04 100644
--- a/cinder/volume/drivers/kaminario/kaminario_iscsi.py
+++ b/cinder/volume/drivers/kaminario/kaminario_iscsi.py
@@ -15,6 +15,7 @@
 """Volume driver for Kaminario K2 all-flash arrays."""
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import coordination
 from cinder.i18n import _
 from cinder import interface
@@ -50,7 +51,7 @@ class KaminarioISCSIDriver(common.KaminarioCinderDriver):
     @volume_utils.trace
     def __init__(self, *args, **kwargs):
         super(KaminarioISCSIDriver, self).__init__(*args, **kwargs)
-        self._protocol = 'iSCSI'
+        self._protocol = constants.ISCSI
 
     @volume_utils.trace
     @coordination.synchronized('{self.k2_lock_name}')
diff --git a/cinder/volume/drivers/kioxia/kumoscale.py b/cinder/volume/drivers/kioxia/kumoscale.py
index f3999bde382..0a2767707fe 100644
--- a/cinder/volume/drivers/kioxia/kumoscale.py
+++ b/cinder/volume/drivers/kioxia/kumoscale.py
@@ -19,6 +19,7 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils.secretutils import md5
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -414,7 +415,7 @@ class KumoScaleBaseVolumeDriver(driver.BaseVD):
             volume_backend_name=self._backend_name,
             vendor_name='KIOXIA',
             driver_version=self.VERSION,
-            storage_protocol='NVMeOF',
+            storage_protocol=constants.NVMEOF_VARIANT_1,
         )
         data['total_capacity_gb'] = 'unknown'
         data['free_capacity_gb'] = 'unknown'
diff --git a/cinder/volume/drivers/lightos.py b/cinder/volume/drivers/lightos.py
index be38ef0ec83..8f4dd073572 100644
--- a/cinder/volume/drivers/lightos.py
+++ b/cinder/volume/drivers/lightos.py
@@ -28,6 +28,7 @@ from oslo_utils import units
 import requests
 import urllib3
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -980,7 +981,6 @@ class LightOSVolumeDriver(driver.VolumeDriver):
 
         backend_name = self.configuration.safe_get('volume_backend_name')
         res_percentage = self.configuration.safe_get('reserved_percentage')
-        storage_protocol = 'lightos'
         # as a tenant we dont have access to cluster stats
         # in the future we might expose this per project via get_project API
         # currently we remove this stats call.
@@ -989,7 +989,7 @@ class LightOSVolumeDriver(driver.VolumeDriver):
         data = {'vendor_name': 'LightOS Storage',
                 'volume_backend_name': backend_name or self.__class__.__name__,
                 'driver_version': self.VERSION,
-                'storage_protocol': storage_protocol,
+                'storage_protocol': constants.LIGHTOS,
                 'reserved_percentage': res_percentage,
                 'QoS_support': False,
                 'online_extend_support': True,
diff --git a/cinder/volume/drivers/linstordrv.py b/cinder/volume/drivers/linstordrv.py
index 9fcfe2f6ac2..c621e275456 100644
--- a/cinder/volume/drivers/linstordrv.py
+++ b/cinder/volume/drivers/linstordrv.py
@@ -27,6 +27,7 @@ from oslo_log import log as logging
 from oslo_utils import importutils
 from oslo_utils import units
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.image import image_utils
@@ -1027,7 +1028,7 @@ class LinstorIscsiDriver(LinstorBaseDriver):
 
     def get_volume_stats(self, refresh=False):
         data = self._get_volume_stats()
-        data["storage_protocol"] = 'iSCSI'
+        data["storage_protocol"] = constants.ISCSI
         data["pools"][0]["location_info"] = (
             'LinstorIscsiDriver:' + data["pools"][0]["location_info"])
 
@@ -1097,7 +1098,7 @@ class LinstorDrbdDriver(LinstorBaseDriver):
 
     def get_volume_stats(self, refresh=False):
         data = self._get_volume_stats()
-        data["storage_protocol"] = 'DRBD'
+        data["storage_protocol"] = constants.DRBD
         data["pools"][0]["location_info"] = 'LinstorDrbdDriver:{}'.format(
             data["pools"][0]["location_info"])
 
diff --git a/cinder/volume/drivers/macrosan/driver.py b/cinder/volume/drivers/macrosan/driver.py
index 4146be9d408..ad02bd801ec 100644
--- a/cinder/volume/drivers/macrosan/driver.py
+++ b/cinder/volume/drivers/macrosan/driver.py
@@ -27,6 +27,7 @@ from oslo_utils import excutils
 from oslo_utils import strutils
 from oslo_utils import timeutils
 
+from cinder.common import constants
 from cinder import context
 from cinder.coordination import synchronized
 from cinder import exception
@@ -1023,7 +1024,7 @@ class MacroSANISCSIDriver(MacroSANBaseDriver, driver.ISCSIDriver):
     def __init__(self, *args, **kwargs):
         """Initialize the driver."""
         super(MacroSANISCSIDriver, self).__init__(*args, **kwargs)
-        self.storage_protocol = 'iSCSI'
+        self.storage_protocol = constants.ISCSI
 
     def _do_setup(self):
         ports = self.client.get_iscsi_ports()
@@ -1224,7 +1225,7 @@ class MacroSANFCDriver(MacroSANBaseDriver, driver.FibreChannelDriver):
     def __init__(self, *args, **kwargs):
         """Initialize the driver."""
         super(MacroSANFCDriver, self).__init__(*args, **kwargs)
-        self.storage_protocol = 'FC'
+        self.storage_protocol = constants.FC
         self.fcsan_lookup_service = None
         self.use_sp_port_nr = self.configuration.macrosan_fc_use_sp_port_nr
         self.keep_mapped_ports = \
diff --git a/cinder/volume/drivers/nec/volume_helper.py b/cinder/volume/drivers/nec/volume_helper.py
index 6bca861ef49..7989c843289 100644
--- a/cinder/volume/drivers/nec/volume_helper.py
+++ b/cinder/volume/drivers/nec/volume_helper.py
@@ -21,6 +21,7 @@ from oslo_log import log as logging
 from oslo_utils import excutils
 from oslo_utils import units
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -1467,7 +1468,7 @@ class MStorageDriver(volume_common.MStorageVolumeCommon):
         """
         if refresh:
             self._stats = self._update_volume_status()
-            self._stats['storage_protocol'] = 'iSCSI'
+            self._stats['storage_protocol'] = constants.ISCSI
         LOG.debug('data=%(data)s, config_group=%(group)s',
                   {'data': self._stats, 'group': self._config_group})
 
@@ -1481,7 +1482,7 @@ class MStorageDriver(volume_common.MStorageVolumeCommon):
 
         if refresh:
             self._stats = self._update_volume_status()
-            self._stats['storage_protocol'] = 'FC'
+            self._stats['storage_protocol'] = constants.FC
         LOG.debug('data=%(data)s, config_group=%(group)s',
                   {'data': self._stats, 'group': self._config_group})
 
diff --git a/cinder/volume/drivers/netapp/dataontap/nfs_cmode.py b/cinder/volume/drivers/netapp/dataontap/nfs_cmode.py
index 54aebb2d463..0cccbef649f 100644
--- a/cinder/volume/drivers/netapp/dataontap/nfs_cmode.py
+++ b/cinder/volume/drivers/netapp/dataontap/nfs_cmode.py
@@ -30,6 +30,7 @@ from oslo_utils import excutils
 from oslo_utils import units
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.image import image_utils
@@ -327,7 +328,7 @@ class NetAppCmodeNfsDriver(nfs_base.NetAppNfsDriver,
         data['volume_backend_name'] = backend_name or self.driver_name
         data['vendor_name'] = 'NetApp'
         data['driver_version'] = self.VERSION
-        data['storage_protocol'] = 'nfs'
+        data['storage_protocol'] = constants.NFS_VARIANT
         data['pools'] = self._get_pool_stats(
             filter_function=self.get_filter_function(),
             goodness_function=self.get_goodness_function())
diff --git a/cinder/volume/drivers/nexenta/iscsi.py b/cinder/volume/drivers/nexenta/iscsi.py
index f359901a056..70e7ee5a679 100644
--- a/cinder/volume/drivers/nexenta/iscsi.py
+++ b/cinder/volume/drivers/nexenta/iscsi.py
@@ -16,6 +16,7 @@ from oslo_log import log as logging
 from oslo_utils import excutils
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -664,7 +665,7 @@ class NexentaISCSIDriver(driver.ISCSIDriver):
             'compression': self.volume_compression,
             'description': self.volume_description,
             'driver_version': self.VERSION,
-            'storage_protocol': 'iSCSI',
+            'storage_protocol': constants.ISCSI,
             'total_capacity_gb': total_amount,
             'free_capacity_gb': free_amount,
             'reserved_percentage': self.configuration.reserved_percentage,
diff --git a/cinder/volume/drivers/nexenta/nfs.py b/cinder/volume/drivers/nexenta/nfs.py
index ffbf2c7e83b..b079c23a0d0 100644
--- a/cinder/volume/drivers/nexenta/nfs.py
+++ b/cinder/volume/drivers/nexenta/nfs.py
@@ -23,6 +23,7 @@ from oslo_utils.secretutils import md5
 from oslo_utils import units
 import six
 
+from cinder.common import constants
 from cinder import context
 from cinder import db
 from cinder import exception
@@ -823,7 +824,7 @@ class NexentaNfsDriver(nfs.NfsDriver):  # pylint: disable=R0921
             'nms_url': nms_url,
             'ns_shares': self.shares_with_capacities,
             'driver_version': self.VERSION,
-            'storage_protocol': 'NFS',
+            'storage_protocol': constants.NFS,
             'total_capacity_gb': total_space,
             'free_capacity_gb': free_space,
             'reserved_percentage': self.configuration.reserved_percentage,
diff --git a/cinder/volume/drivers/nexenta/ns5/iscsi.py b/cinder/volume/drivers/nexenta/ns5/iscsi.py
index bf8d3f3cb06..7b67aeb9dd1 100644
--- a/cinder/volume/drivers/nexenta/ns5/iscsi.py
+++ b/cinder/volume/drivers/nexenta/ns5/iscsi.py
@@ -22,6 +22,7 @@ from oslo_log import log as logging
 from oslo_utils import units
 import six
 
+from cinder.common import constants
 from cinder import context
 from cinder import coordination
 from cinder.i18n import _
@@ -77,7 +78,7 @@ class NexentaISCSIDriver(driver.ISCSIDriver):
 
     vendor_name = 'Nexenta'
     product_name = 'NexentaStor5'
-    storage_protocol = 'iSCSI'
+    storage_protocol = constants.ISCSI
     driver_volume_type = 'iscsi'
 
     def __init__(self, *args, **kwargs):
diff --git a/cinder/volume/drivers/nexenta/ns5/nfs.py b/cinder/volume/drivers/nexenta/ns5/nfs.py
index 61de0d7d681..8573fc42e17 100644
--- a/cinder/volume/drivers/nexenta/ns5/nfs.py
+++ b/cinder/volume/drivers/nexenta/ns5/nfs.py
@@ -23,6 +23,7 @@ from oslo_utils.secretutils import md5
 from oslo_utils import units
 import six
 
+from cinder.common import constants
 from cinder import context
 from cinder import coordination
 from cinder.i18n import _
@@ -88,7 +89,7 @@ class NexentaNfsDriver(nfs.NfsDriver):
 
     vendor_name = 'Nexenta'
     product_name = 'NexentaStor5'
-    storage_protocol = 'NFS'
+    storage_protocol = constants.NFS
     driver_volume_type = 'nfs'
 
     def __init__(self, *args, **kwargs):
diff --git a/cinder/volume/drivers/open_e/iscsi.py b/cinder/volume/drivers/open_e/iscsi.py
index cfb006fb926..3117b6342d2 100644
--- a/cinder/volume/drivers/open_e/iscsi.py
+++ b/cinder/volume/drivers/open_e/iscsi.py
@@ -20,6 +20,7 @@ import string
 from oslo_log import log as logging
 from oslo_utils import units as o_units
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -743,7 +744,7 @@ class JovianISCSIDriver(driver.ISCSIDriver):
         self._stats = {
             'vendor_name': 'Open-E',
             'driver_version': self.VERSION,
-            'storage_protocol': 'iSCSI',
+            'storage_protocol': constants.ISCSI,
             'total_capacity_gb': total_capacity,
             'free_capacity_gb': free_capacity,
             'reserved_percentage': int(reserved_percentage),
diff --git a/cinder/volume/drivers/prophetstor/dpl_fc.py b/cinder/volume/drivers/prophetstor/dpl_fc.py
index b2c76094778..145700bacec 100644
--- a/cinder/volume/drivers/prophetstor/dpl_fc.py
+++ b/cinder/volume/drivers/prophetstor/dpl_fc.py
@@ -17,6 +17,7 @@ import errno
 
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -389,7 +390,7 @@ class DPLFCDriver(dplcommon.DPLCOMMONDriver,
         if refresh:
             data = super(DPLFCDriver, self).get_volume_stats(refresh)
             if data:
-                data['storage_protocol'] = 'FC'
+                data['storage_protocol'] = constants.FC
                 backend_name = \
                     self.configuration.safe_get('volume_backend_name')
                 data['volume_backend_name'] = (backend_name or 'DPLFCDriver')
diff --git a/cinder/volume/drivers/prophetstor/dpl_iscsi.py b/cinder/volume/drivers/prophetstor/dpl_iscsi.py
index f922e5dca57..413b62f6e90 100644
--- a/cinder/volume/drivers/prophetstor/dpl_iscsi.py
+++ b/cinder/volume/drivers/prophetstor/dpl_iscsi.py
@@ -17,6 +17,7 @@ import errno
 
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -144,7 +145,7 @@ class DPLISCSIDriver(dplcommon.DPLCOMMONDriver,
             try:
                 data = super(DPLISCSIDriver, self).get_volume_stats(refresh)
                 if data:
-                    data['storage_protocol'] = 'iSCSI'
+                    data['storage_protocol'] = constants.ISCSI
                     backend_name = \
                         self.configuration.safe_get('volume_backend_name')
                     data['volume_backend_name'] = \
diff --git a/cinder/volume/drivers/prophetstor/dplcommon.py b/cinder/volume/drivers/prophetstor/dplcommon.py
index 9d69ec4bea4..2cde1c5133e 100644
--- a/cinder/volume/drivers/prophetstor/dplcommon.py
+++ b/cinder/volume/drivers/prophetstor/dplcommon.py
@@ -34,6 +34,7 @@ import requests
 import six
 from six.moves import http_client
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import objects
@@ -1455,7 +1456,7 @@ class DPLCOMMONDriver(driver.CloneableImageVD,
             if ret == 0:
                 data['vendor_name'] = output['metadata']['vendor']
                 data['driver_version'] = output['metadata']['version']
-                data['storage_protocol'] = 'iSCSI'
+                data['storage_protocol'] = constants.ISCSI
                 data['location_info'] = location_info
                 data['consistencygroup_support'] = True
                 data['consistent_group_snapshot_enabled'] = True
diff --git a/cinder/volume/drivers/pure.py b/cinder/volume/drivers/pure.py
index 01cffb99918..95cfa6c4107 100644
--- a/cinder/volume/drivers/pure.py
+++ b/cinder/volume/drivers/pure.py
@@ -35,6 +35,7 @@ try:
 except ImportError:
     purestorage = None
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -2526,7 +2527,7 @@ class PureISCSIDriver(PureBaseVolumeDriver, san.SanISCSIDriver):
     def __init__(self, *args, **kwargs):
         execute = kwargs.pop("execute", utils.execute)
         super(PureISCSIDriver, self).__init__(execute=execute, *args, **kwargs)
-        self._storage_protocol = "iSCSI"
+        self._storage_protocol = constants.ISCSI
 
     def _get_host(self, array, connector, remote=False):
         """Return dict describing existing Purity host object or None."""
@@ -2748,7 +2749,7 @@ class PureFCDriver(PureBaseVolumeDriver, driver.FibreChannelDriver):
     def __init__(self, *args, **kwargs):
         execute = kwargs.pop("execute", utils.execute)
         super(PureFCDriver, self).__init__(execute=execute, *args, **kwargs)
-        self._storage_protocol = "FC"
+        self._storage_protocol = constants.FC
         self._lookup_service = fczm_utils.create_lookup_service()
 
     def _get_host(self, array, connector, remote=False):
diff --git a/cinder/volume/drivers/qnap.py b/cinder/volume/drivers/qnap.py
index d963d037527..362083b8217 100644
--- a/cinder/volume/drivers/qnap.py
+++ b/cinder/volume/drivers/qnap.py
@@ -35,6 +35,7 @@ import requests
 import six
 from six.moves import urllib
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -51,7 +52,7 @@ qnap_opts = [
     cfg.StrOpt('qnap_poolname',
                help='The pool name in the QNAP Storage'),
     cfg.StrOpt('qnap_storage_protocol',
-               default='iscsi',
+               default=constants.ISCSI,
                help='Communication protocol to access QNAP storage')
 ]
 
diff --git a/cinder/volume/drivers/rbd.py b/cinder/volume/drivers/rbd.py
index 16a484536f0..9dbd973520e 100644
--- a/cinder/volume/drivers/rbd.py
+++ b/cinder/volume/drivers/rbd.py
@@ -40,6 +40,7 @@ except ImportError:
     rados = None
     rbd = None
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -243,7 +244,7 @@ class RBDDriver(driver.CloneableImageVD, driver.MigrateVD,
     RBD_FEATURE_OBJECT_MAP = 8
     RBD_FEATURE_FAST_DIFF = 16
     RBD_FEATURE_JOURNALING = 64
-    STORAGE_PROTOCOL = 'ceph'
+    STORAGE_PROTOCOL = constants.CEPH
 
     def __init__(self,
                  active_backend_id: str = None,
@@ -2065,7 +2066,7 @@ class RBDDriver(driver.CloneableImageVD, driver.MigrateVD,
                       'migration.')
             return refuse_to_migrate
 
-        if (host['capabilities']['storage_protocol'] != 'ceph'):
+        if (host['capabilities']['storage_protocol'] != self.STORAGE_PROTOCOL):
             LOG.debug('Source and destination drivers need to be RBD '
                       'to use backend assisted migration. Falling back to '
                       'generic migration.')
diff --git a/cinder/volume/drivers/rsd.py b/cinder/volume/drivers/rsd.py
index e0e1013dd05..fc90168f842 100644
--- a/cinder/volume/drivers/rsd.py
+++ b/cinder/volume/drivers/rsd.py
@@ -26,6 +26,7 @@ except ImportError:
     RSDLib = None
     sushy_exceptions = None
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -594,7 +595,7 @@ class RSDDriver(driver.VolumeDriver):
         self._stats['volume_backend_name'] = backend_name
         self._stats['vendor_name'] = 'Intel'
         self._stats['driver_version'] = self.VERSION
-        self._stats['storage_protocol'] = 'nvmeof'
+        self._stats['storage_protocol'] = constants.NVMEOF_VARIANT_2
         # SinglePool
         self._stats['pools'] = [spool]
 
diff --git a/cinder/volume/drivers/sandstone/sds_driver.py b/cinder/volume/drivers/sandstone/sds_driver.py
index 32cb9ac6f33..52924dcaf0b 100644
--- a/cinder/volume/drivers/sandstone/sds_driver.py
+++ b/cinder/volume/drivers/sandstone/sds_driver.py
@@ -18,6 +18,7 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import units
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -334,7 +335,7 @@ class SdsISCSIDriver(SdsBaseDriver, driver.ISCSIDriver):
         data = SdsBaseDriver.get_volume_stats(self, refresh)
         backend_name = self.configuration.safe_get('volume_backend_name')
         data['volume_backend_name'] = backend_name or self.__class__.__name__
-        data['storage_protocol'] = 'iSCSI'
+        data['storage_protocol'] = constants.ISCSI
         data['driver_version'] = self.VERSION
         data['vendor_name'] = 'SandStone USP'
         return data
diff --git a/cinder/volume/drivers/solidfire.py b/cinder/volume/drivers/solidfire.py
index 522cae8546a..5527633c222 100644
--- a/cinder/volume/drivers/solidfire.py
+++ b/cinder/volume/drivers/solidfire.py
@@ -31,6 +31,7 @@ from oslo_utils import units
 import requests
 import six
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -2163,7 +2164,7 @@ class SolidFireDriver(san.SanISCSIDriver):
         data["volume_backend_name"] = backend_name or self.__class__.__name__
         data["vendor_name"] = 'SolidFire Inc'
         data["driver_version"] = self.VERSION
-        data["storage_protocol"] = 'iSCSI'
+        data["storage_protocol"] = constants.ISCSI
         data['consistencygroup_support'] = True
         data['consistent_group_snapshot_enabled'] = True
         data['replication_enabled'] = self.replication_enabled
diff --git a/cinder/volume/drivers/spdk.py b/cinder/volume/drivers/spdk.py
index 80be966be7a..34c7b1fe676 100644
--- a/cinder/volume/drivers/spdk.py
+++ b/cinder/volume/drivers/spdk.py
@@ -19,6 +19,7 @@ from oslo_utils import importutils
 from oslo_utils import units
 import requests
 
+from cinder.common import constants
 from cinder import context
 from cinder import exception
 from cinder.i18n import _
@@ -91,7 +92,7 @@ class SPDKDriver(driver.VolumeDriver):
         status = {'volume_backend_name': 'SPDK',
                   'vendor_name': 'Open Source',
                   'driver_version': self.VERSION,
-                  'storage_protocol': 'NVMe-oF'}
+                  'storage_protocol': constants.NVMEOF}
         pools_status = []
         self.lvs = []
 
@@ -109,7 +110,7 @@ class SPDKDriver(driver.VolumeDriver):
                 pool["volume_backend_name"] = 'SPDK'
                 pool["vendor_name"] = 'Open Source'
                 pool["driver_version"] = self.VERSION
-                pool["storage_protocol"] = 'NVMe-oF'
+                pool["storage_protocol"] = constants.NVMEOF
                 pool["total_capacity_gb"] = total_size
                 pool["free_capacity_gb"] = free_size
                 pool["pool_name"] = lvs['name']
diff --git a/cinder/volume/drivers/storpool.py b/cinder/volume/drivers/storpool.py
index cf5707cbc7e..47685cb3f51 100644
--- a/cinder/volume/drivers/storpool.py
+++ b/cinder/volume/drivers/storpool.py
@@ -23,6 +23,7 @@ from oslo_utils import importutils
 from oslo_utils import units
 import six
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -305,7 +306,7 @@ class StorPoolDriver(driver.VolumeDriver):
                 'volume_backend_name') or 'storpool',
             'vendor_name': 'StorPool',
             'driver_version': self.VERSION,
-            'storage_protocol': 'storpool',
+            'storage_protocol': constants.STORPOOL,
 
             'sparse_copy_volume': True,
 
diff --git a/cinder/volume/drivers/stx/fc.py b/cinder/volume/drivers/stx/fc.py
index e7b60b4e6cc..8a58a4b9384 100644
--- a/cinder/volume/drivers/stx/fc.py
+++ b/cinder/volume/drivers/stx/fc.py
@@ -15,6 +15,7 @@
 #    under the License.
 #
 
+from cinder.common import constants
 import cinder.volume.driver
 import cinder.volume.drivers.san.san as san
 import cinder.volume.drivers.stx.common as common
@@ -146,7 +147,7 @@ class STXFCDriver(cinder.volume.driver.FibreChannelDriver):
 
     def get_volume_stats(self, refresh=False):
         stats = self.common.get_volume_stats(refresh)
-        stats['storage_protocol'] = 'FC'
+        stats['storage_protocol'] = constants.FC
         stats['driver_version'] = self.VERSION
         backend_name = self.configuration.safe_get('volume_backend_name')
         stats['volume_backend_name'] = (backend_name or
diff --git a/cinder/volume/drivers/stx/iscsi.py b/cinder/volume/drivers/stx/iscsi.py
index 787aa4d52b9..5c57b520b09 100644
--- a/cinder/volume/drivers/stx/iscsi.py
+++ b/cinder/volume/drivers/stx/iscsi.py
@@ -17,6 +17,7 @@
 
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 import cinder.volume.driver
@@ -161,7 +162,7 @@ class STXISCSIDriver(cinder.volume.driver.ISCSIDriver):
 
     def get_volume_stats(self, refresh=False):
         stats = self.common.get_volume_stats(refresh)
-        stats['storage_protocol'] = 'iSCSI'
+        stats['storage_protocol'] = constants.ISCSI
         stats['driver_version'] = self.VERSION
         backend_name = self.configuration.safe_get('volume_backend_name')
         stats['volume_backend_name'] = (backend_name or
diff --git a/cinder/volume/drivers/toyou/acs5000/acs5000_common.py b/cinder/volume/drivers/toyou/acs5000/acs5000_common.py
index 17b34f8ac82..a8ff3807222 100644
--- a/cinder/volume/drivers/toyou/acs5000/acs5000_common.py
+++ b/cinder/volume/drivers/toyou/acs5000/acs5000_common.py
@@ -30,6 +30,7 @@ from oslo_utils import excutils
 from oslo_utils import units
 import paramiko
 
+from cinder.common import constants
 from cinder import coordination
 from cinder import exception
 from cinder.i18n import _
@@ -355,7 +356,7 @@ class Acs5000CommonDriver(san.SanDriver,
         self._state.update(self._cmd.get_system())
 
         self._state['controller'] = self._cmd.ls_controller()
-        if self.protocol == 'FC':
+        if self.protocol == constants.FC:
             ports = self._cmd.ls_fc()
         else:
             ports = self._cmd.ls_iscsi()
diff --git a/cinder/volume/drivers/toyou/acs5000/acs5000_fc.py b/cinder/volume/drivers/toyou/acs5000/acs5000_fc.py
index e974df345e7..a97474688c5 100644
--- a/cinder/volume/drivers/toyou/acs5000/acs5000_fc.py
+++ b/cinder/volume/drivers/toyou/acs5000/acs5000_fc.py
@@ -19,6 +19,7 @@ acs5000 FC driver
 
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -42,7 +43,7 @@ class Acs5000FCDriver(acs5000_common.Acs5000CommonDriver):
 
     VENDOR = 'TOYOU'
     VERSION = '1.0.0'
-    PROTOCOL = 'FC'
+    PROTOCOL = constants.FC
 
     # ThirdPartySystems wiki page
     CI_WIKI_NAME = 'TOYOU_ACS5000_CI'
diff --git a/cinder/volume/drivers/toyou/acs5000/acs5000_iscsi.py b/cinder/volume/drivers/toyou/acs5000/acs5000_iscsi.py
index ce9b4715b70..95221693d76 100644
--- a/cinder/volume/drivers/toyou/acs5000/acs5000_iscsi.py
+++ b/cinder/volume/drivers/toyou/acs5000/acs5000_iscsi.py
@@ -19,6 +19,7 @@ acs5000 iSCSI driver
 
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -41,7 +42,7 @@ class Acs5000ISCSIDriver(acs5000_common.Acs5000CommonDriver):
 
     VENDOR = 'TOYOU'
     VERSION = '1.0.0'
-    PROTOCOL = 'iSCSI'
+    PROTOCOL = constants.ISCSI
 
     # ThirdPartySystems wiki page
     CI_WIKI_NAME = 'TOYOU_ACS5000_CI'
diff --git a/cinder/volume/drivers/veritas_access/veritas_iscsi.py b/cinder/volume/drivers/veritas_access/veritas_iscsi.py
index 4b3f69e6ecd..1b88f28ff65 100644
--- a/cinder/volume/drivers/veritas_access/veritas_iscsi.py
+++ b/cinder/volume/drivers/veritas_access/veritas_iscsi.py
@@ -31,6 +31,7 @@ import requests
 import requests.auth
 from six.moves import http_client
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -85,7 +86,6 @@ class ACCESSIscsiDriver(driver.ISCSIDriver):
     VERSION = "1.0"
     # ThirdPartySytems wiki page
     CI_WIKI_NAME = "Veritas_Access_CI"
-    DRIVER_VOLUME_TYPE = 'iSCSI'
     LUN_FOUND_INTERVAL = 30  # seconds
 
     # TODO(jsbryant) Remove driver in the 'U' release if CI is not fixed.
@@ -892,7 +892,7 @@ class ACCESSIscsiDriver(driver.ISCSIDriver):
         self._stats["vendor_name"] = 'Veritas'
         self._stats["reserved_percentage"] = res_percentage or 0
         self._stats["driver_version"] = self.VERSION
-        self._stats["storage_protocol"] = self.DRIVER_VOLUME_TYPE
+        self._stats["storage_protocol"] = constants.ISCSI
         self._stats['total_capacity_gb'] = total_capacity
         self._stats['free_capacity_gb'] = free_capacity
         self._stats['thin_provisioning_support'] = True
diff --git a/cinder/volume/drivers/veritas_cnfs.py b/cinder/volume/drivers/veritas_cnfs.py
index 25e36c036c6..33c9d30f1de 100644
--- a/cinder/volume/drivers/veritas_cnfs.py
+++ b/cinder/volume/drivers/veritas_cnfs.py
@@ -18,6 +18,7 @@ import os
 from oslo_log import log as logging
 from oslo_utils import excutils
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -52,7 +53,7 @@ class VeritasCNFSDriver(nfs.NfsDriver):
     VERSION = "1.0.3"
     # ThirdPartySytems wiki page
     CI_WIKI_NAME = "Veritas_Access_CI"
-    DRIVER_VOLUME_TYPE = 'nfs'
+    DRIVER_VOLUME_TYPE = constants.NFS_VARIANT
 
     # TODO(jsbryant) Remove driver in the 'V' release if CI is not fixed.
     SUPPORTED = False
diff --git a/cinder/volume/drivers/vmware/fcd.py b/cinder/volume/drivers/vmware/fcd.py
index b77c14b8406..ca8a06f482c 100644
--- a/cinder/volume/drivers/vmware/fcd.py
+++ b/cinder/volume/drivers/vmware/fcd.py
@@ -27,6 +27,7 @@ from oslo_vmware import image_transfer
 from oslo_vmware.objects import datastore
 from oslo_vmware import vim_util
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import interface
@@ -55,7 +56,7 @@ class VMwareVStorageObjectDriver(vmdk.VMwareVcVmdkDriver):
     # minimum supported vCenter version
     MIN_SUPPORTED_VC_VERSION = '6.5'
 
-    STORAGE_TYPE = 'vstorageobject'
+    STORAGE_TYPE = constants.VSTORAGE
 
     def do_setup(self, context):
         """Any initialization the volume driver needs to do while starting.
diff --git a/cinder/volume/drivers/vmware/vmdk.py b/cinder/volume/drivers/vmware/vmdk.py
index 065601b09eb..2e81cbaa156 100644
--- a/cinder/volume/drivers/vmware/vmdk.py
+++ b/cinder/volume/drivers/vmware/vmdk.py
@@ -37,6 +37,7 @@ from oslo_vmware import image_transfer
 from oslo_vmware import pbm
 from oslo_vmware import vim_util
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.image import image_utils
@@ -369,7 +370,7 @@ class VMwareVcVmdkDriver(driver.VolumeDriver):
         data = {'volume_backend_name': backend_name,
                 'vendor_name': 'VMware',
                 'driver_version': self.VERSION,
-                'storage_protocol': 'vmdk',
+                'storage_protocol': constants.VMDK,
                 'reserved_percentage': self.configuration.reserved_percentage,
                 'shared_targets': False}
         ds_summaries = self._get_datastore_summaries()
diff --git a/cinder/volume/drivers/windows/iscsi.py b/cinder/volume/drivers/windows/iscsi.py
index 83cc02d412a..61635612782 100644
--- a/cinder/volume/drivers/windows/iscsi.py
+++ b/cinder/volume/drivers/windows/iscsi.py
@@ -29,6 +29,7 @@ from oslo_utils import fileutils
 from oslo_utils import units
 from oslo_utils import uuidutils
 
+from cinder.common import constants
 from cinder import exception
 from cinder.image import image_utils
 from cinder import interface
@@ -334,7 +335,7 @@ class WindowsISCSIDriver(driver.ISCSIDriver):
         data["volume_backend_name"] = backend_name or self.__class__.__name__
         data["vendor_name"] = 'Microsoft'
         data["driver_version"] = self.VERSION
-        data["storage_protocol"] = 'iSCSI'
+        data["storage_protocol"] = constants.ISCSI
         data['total_capacity_gb'] = total_gb
         data['free_capacity_gb'] = free_gb
         data['reserved_percentage'] = self.configuration.reserved_percentage
diff --git a/cinder/volume/drivers/zadara/zadara.py b/cinder/volume/drivers/zadara/zadara.py
index e97468a6fb3..5a7895e6431 100644
--- a/cinder/volume/drivers/zadara/zadara.py
+++ b/cinder/volume/drivers/zadara/zadara.py
@@ -22,6 +22,7 @@ from oslo_log import log as logging
 from oslo_utils import strutils
 import six
 
+from cinder.common import constants
 from cinder import exception as cinder_exception
 from cinder.i18n import _
 from cinder import interface
@@ -709,9 +710,9 @@ class ZadaraVPSAISCSIDriver(driver.ISCSIDriver):
         """Retrieve stats info from volume group."""
         LOG.debug("Updating volume stats")
         backend_name = self.configuration.safe_get('volume_backend_name')
-        storage_protocol = ('iSER' if
+        storage_protocol = (constants.ISER if
                             (self.configuration.safe_get('zadara_use_iser'))
-                            else 'iSCSI')
+                            else constants.ISCSI)
         pool_name = self.configuration.zadara_vpsa_poolname
         (total, free, provisioned) = self.vpsa._get_pool_capacity(pool_name)
         data = dict(
diff --git a/cinder/volume/manager.py b/cinder/volume/manager.py
index 2b11b9ffec4..9101ceb1fac 100644
--- a/cinder/volume/manager.py
+++ b/cinder/volume/manager.py
@@ -844,9 +844,10 @@ class VolumeManager(manager.CleanableManager,
 
         # Shared targets is only relevant for iSCSI connections.
         # We default to True to be on the safe side.
+        capabilities = self.driver.capabilities
         volume.shared_targets = (
-            self.driver.capabilities.get('storage_protocol') == 'iSCSI' and
-            self.driver.capabilities.get('shared_targets', True))
+            capabilities.get('storage_protocol') in constants.ISCSI_VARIANTS
+            and capabilities.get('shared_targets', True))
         # TODO(geguileo): service_uuid won't be enough on Active/Active
         # deployments. There can be 2 services handling volumes from the same
         # backend.
@@ -2761,8 +2762,8 @@ class VolumeManager(manager.CleanableManager,
 
             # Append cacheable flag for iSCSI/FC/NVMe-oF and only when
             # cacheable is not set in driver level
-            if volume_stats.get('storage_protocol') in [
-                    'iSCSI', 'FC', 'NVMe-oF']:
+            if (volume_stats.get('storage_protocol')
+                    in constants.CACHEABLE_PROTOCOLS):
                 if volume_stats.get('pools'):
                     for pool in volume_stats.get('pools'):
                         if pool.get('cacheable') is None:
diff --git a/cinder/volume/targets/iscsi.py b/cinder/volume/targets/iscsi.py
index 7303e7e7c68..1e89a06c3ef 100644
--- a/cinder/volume/targets/iscsi.py
+++ b/cinder/volume/targets/iscsi.py
@@ -15,6 +15,7 @@ import abc
 from oslo_concurrency import processutils
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder import utils
@@ -37,7 +38,7 @@ class ISCSITarget(driver.Target):
         super(ISCSITarget, self).__init__(*args, **kwargs)
         self.iscsi_target_prefix = self.configuration.safe_get('target_prefix')
         self.iscsi_protocol = self.configuration.safe_get('target_protocol')
-        self.protocol = 'iSCSI'
+        self.protocol = constants.ISCSI
         self.volumes_dir = self.configuration.safe_get('volumes_dir')
 
     def _get_iscsi_properties(self, volume, multipath=False):
diff --git a/cinder/volume/targets/nvmeof.py b/cinder/volume/targets/nvmeof.py
index f250f60c7eb..0992de1c960 100644
--- a/cinder/volume/targets/nvmeof.py
+++ b/cinder/volume/targets/nvmeof.py
@@ -14,6 +14,7 @@ import abc
 
 from oslo_log import log as logging
 
+from cinder.common import constants
 from cinder import exception
 from cinder.i18n import _
 from cinder.volume.targets import driver
@@ -31,7 +32,7 @@ class NVMeOF(driver.Target):
 
     """Target object for block storage devices with RDMA transport."""
 
-    protocol = 'nvmeof'
+    protocol = constants.NVMEOF_VARIANT_2
     target_protocol_map = {
         'nvmet_rdma': 'rdma',
         'nvmet_tcp': 'tcp',
diff --git a/releasenotes/notes/fix-cacheable-capability-f893520d79c3db60.yaml b/releasenotes/notes/fix-cacheable-capability-f893520d79c3db60.yaml
new file mode 100644
index 00000000000..7834068678e
--- /dev/null
+++ b/releasenotes/notes/fix-cacheable-capability-f893520d79c3db60.yaml
@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    `Bug #1969366 <https://bugs.launchpad.net/cinder/+bug/1969366>`_: Fixed
+    reporting of cacheable capability by drivers.