diff --git a/environments/storage/cinder-netapp-config.yaml b/environments/storage/cinder-netapp-config.yaml
index 36568458d9..5375c67549 100644
--- a/environments/storage/cinder-netapp-config.yaml
+++ b/environments/storage/cinder-netapp-config.yaml
@@ -9,6 +9,10 @@
 #   A Heat environment file which can be used to enable a
 #   a Cinder NetApp backend, configured via puppet
 parameter_defaults:
+  # The availability zone of the NetApp Cinder backend. When set, it overrides the default CinderStorageAvailabilityZone.
+  # Type: string
+  CinderNetappAvailabilityZone: ''
+
   # 
   # Type: string
   CinderNetappBackendName: tripleo_netapp
diff --git a/puppet/services/cinder-backend-dellemc-unity.yaml b/puppet/services/cinder-backend-dellemc-unity.yaml
index 668335d10b..4f748bf755 100644
--- a/puppet/services/cinder-backend-dellemc-unity.yaml
+++ b/puppet/services/cinder-backend-dellemc-unity.yaml
@@ -23,6 +23,12 @@ parameters:
   CinderDellEMCUnityBackendName:
     type: string
     default: 'tripleo_dellemc_unity'
+  CinderDellEMCUnityAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Dell EMC Unity Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderDellEMCUnitySanIp:
     type: string
   CinderDellEMCUnitySanLogin:
@@ -73,11 +79,17 @@ outputs:
     value:
       service_name: cinder_backend_dellemc_unity
       config_settings:
-                tripleo::profile::base::cinder::volume::cinder_enable_dellemc_unity_backend: {get_param: CinderEnableDellEMCUnityBackend}
-                cinder::backend::dellemc_unity::volume_backend_name: {get_param: CinderDellEMCUnityBackendName}
-                cinder::backend::dellemc_unity::san_ip: {get_param: CinderDellEMCUnitySanIp}
-                cinder::backend::dellemc_unity::san_login: {get_param: CinderDellEMCUnitySanLogin}
-                cinder::backend::dellemc_unity::san_password: {get_param: CinderDellEMCUnitySanPassword}
-                cinder::backend::dellemc_unity::storage_protocol: {get_param: CinderDellEMCUnityStorageProtocol}
-                cinder::backend::dellemc_unity::unity_io_ports: {get_param: CinderDellEMCUnityIoPorts}
-                cinder::backend::dellemc_unity::unity_storage_pool_names: {get_param: CinderDellEMCUnityStoragePoolNames}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_dellemc_unity_backend: {get_param: CinderEnableDellEMCUnityBackend}
+            cinder::backend::dellemc_unity::volume_backend_name: {get_param: CinderDellEMCUnityBackendName}
+            cinder::backend::dellemc_unity::san_ip: {get_param: CinderDellEMCUnitySanIp}
+            cinder::backend::dellemc_unity::san_login: {get_param: CinderDellEMCUnitySanLogin}
+            cinder::backend::dellemc_unity::san_password: {get_param: CinderDellEMCUnitySanPassword}
+            cinder::backend::dellemc_unity::storage_protocol: {get_param: CinderDellEMCUnityStorageProtocol}
+            cinder::backend::dellemc_unity::unity_io_ports: {get_param: CinderDellEMCUnityIoPorts}
+            cinder::backend::dellemc_unity::unity_storage_pool_names: {get_param: CinderDellEMCUnityStoragePoolNames}
+          -
+            if:
+            - {equals : [{get_param: CinderDellEMCUnityAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::dellemc_unity::backend_availability_zone: {get_param: CinderDellEMCUnityAvailabilityZone}
diff --git a/puppet/services/cinder-backend-dellemc-vmax-iscsi.yaml b/puppet/services/cinder-backend-dellemc-vmax-iscsi.yaml
index 403a9fd8a2..109513ec7b 100644
--- a/puppet/services/cinder-backend-dellemc-vmax-iscsi.yaml
+++ b/puppet/services/cinder-backend-dellemc-vmax-iscsi.yaml
@@ -23,6 +23,12 @@ parameters:
   CinderDellEMCVMAXISCSIBackendName:
     type: string
     default: 'tripleo_dellemc_vmax_iscsi'
+  CinderDellEMCVMAXISCSIAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Dell EMC VMAX iSCSI Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderDellEMCVMAXISCSIConfigFile:
     type: string
   ServiceData:
@@ -58,6 +64,12 @@ outputs:
     value:
       service_name: cinder_backend_dellemc_vmax_iscsi
       config_settings:
-                tripleo::profile::base::cinder::volume::cinder_enable_dellemc_vmax_iscsi_backend: {get_param: CinderEnableDellEMCVMAXISCSIBackend}
-                cinder::backend::dellemc_vmax_iscsi::volume_backend_name: {get_param: CinderDellEMCVMAXISCSIBackendName}
-                cinder::backend::dellemc_vmax_iscsi::cinder_emc_config_file: {get_param: CinderDellEMCVMAXISCSIConfigFile}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_dellemc_vmax_iscsi_backend: {get_param: CinderEnableDellEMCVMAXISCSIBackend}
+            cinder::backend::dellemc_vmax_iscsi::volume_backend_name: {get_param: CinderDellEMCVMAXISCSIBackendName}
+            cinder::backend::dellemc_vmax_iscsi::cinder_emc_config_file: {get_param: CinderDellEMCVMAXISCSIConfigFile}
+          -
+            if:
+            - {equals : [{get_param: CinderDellEMCVMAXISCSIAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::dellemc_vmax_iscsi::backend_availability_zone: {get_param: CinderDellEMCVMAXISCSIAvailabilityZone}
diff --git a/puppet/services/cinder-backend-dellemc-vnx.yaml b/puppet/services/cinder-backend-dellemc-vnx.yaml
index 9655ea0daf..b6b428ae9e 100644
--- a/puppet/services/cinder-backend-dellemc-vnx.yaml
+++ b/puppet/services/cinder-backend-dellemc-vnx.yaml
@@ -23,6 +23,12 @@ parameters:
   CinderDellEMCVNXBackendName:
     type: string
     default: tripleo_dellemc_vnx
+  CinderDellEMCVNXAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Dell EMC VNX Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderDellEMCVNXSanIp:
     type: string
   CinderDellEMCVNXSanLogin:
@@ -89,16 +95,22 @@ outputs:
     value:
       service_name: cinder_backend_dellemc_vnx
       config_settings:
-                tripleo::profile::base::cinder::volume::cinder_enable_dellemc_vnx_backend: {get_param: CinderEnableDellEMCVNXBackend}
-                cinder::backend::emc_vnx::volume_backend_name: {get_param: CinderDellEMCVNXBackendName}
-                cinder::backend::emc_vnx::san_ip: {get_param: CinderDellEMCVNXSanIp}
-                cinder::backend::emc_vnx::san_login: {get_param: CinderDellEMCVNXSanLogin}
-                cinder::backend::emc_vnx::san_password: {get_param: CinderDellEMCVNXSanPassword}
-                cinder::backend::emc_vnx::storage_protocol: {get_param: CinderDellEMCVNXStorageProtocol}
-                cinder::backend::emc_vnx::storage_vnx_pool_names: {get_param: CinderDellEMCVNXStoragePoolNames}
-                cinder::backend::emc_vnx::default_timeout: {get_param: CinderDellEMCVNXDefaultTimeout}
-                cinder::backend::emc_vnx::max_luns_per_storage_group: {get_param: CinderDellEMCVNXMaxLunsPerStorageGroup}
-                cinder::backend::emc_vnx::initiator_auto_registration: {get_param: CinderDellEMCVNXInitiatorAutoRegistration}
-                cinder::backend::emc_vnx::storage_vnx_auth_type: {get_param: CinderDellEMCVNXAuthType}
-                cinder::backend::emc_vnx::storage_vnx_security_file_dir: {get_param: CinderDellEMCVNXStorageSecurityFileDir}
-                cinder::backend::emc_vnx::naviseccli_path: {get_param: CinderDellEMCVNXNaviSecCliPath}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_dellemc_vnx_backend: {get_param: CinderEnableDellEMCVNXBackend}
+            cinder::backend::emc_vnx::volume_backend_name: {get_param: CinderDellEMCVNXBackendName}
+            cinder::backend::emc_vnx::san_ip: {get_param: CinderDellEMCVNXSanIp}
+            cinder::backend::emc_vnx::san_login: {get_param: CinderDellEMCVNXSanLogin}
+            cinder::backend::emc_vnx::san_password: {get_param: CinderDellEMCVNXSanPassword}
+            cinder::backend::emc_vnx::storage_protocol: {get_param: CinderDellEMCVNXStorageProtocol}
+            cinder::backend::emc_vnx::storage_vnx_pool_names: {get_param: CinderDellEMCVNXStoragePoolNames}
+            cinder::backend::emc_vnx::default_timeout: {get_param: CinderDellEMCVNXDefaultTimeout}
+            cinder::backend::emc_vnx::max_luns_per_storage_group: {get_param: CinderDellEMCVNXMaxLunsPerStorageGroup}
+            cinder::backend::emc_vnx::initiator_auto_registration: {get_param: CinderDellEMCVNXInitiatorAutoRegistration}
+            cinder::backend::emc_vnx::storage_vnx_auth_type: {get_param: CinderDellEMCVNXAuthType}
+            cinder::backend::emc_vnx::storage_vnx_security_file_dir: {get_param: CinderDellEMCVNXStorageSecurityFileDir}
+            cinder::backend::emc_vnx::naviseccli_path: {get_param: CinderDellEMCVNXNaviSecCliPath}
+          -
+            if:
+            - {equals : [{get_param: CinderDellEMCVNXAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::emc_vnx::backend_availability_zone: {get_param: CinderDellEMCVNXAvailabilityZone}
diff --git a/puppet/services/cinder-backend-dellemc-xtremio-iscsi.yaml b/puppet/services/cinder-backend-dellemc-xtremio-iscsi.yaml
index 40d67e4847..c4bf826803 100644
--- a/puppet/services/cinder-backend-dellemc-xtremio-iscsi.yaml
+++ b/puppet/services/cinder-backend-dellemc-xtremio-iscsi.yaml
@@ -23,6 +23,12 @@ parameters:
   CinderDellEMCXTREMIOIscsiBackendName:
     type: string
     default: tripleo_dellemc_xtremio_iscsi
+  CinderDellEMCXTREMIOIscsiAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Dell EMC XtremeIO iSCSI Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderDellEMCXTREMIOIscsiSanIp:
     type: string
   CinderDellEMCXTREMIOIscsiSanLogin:
@@ -80,12 +86,18 @@ outputs:
     value:
       service_name: cinder_backend_dellemc_xtremio_iscsi
       config_settings:
-                tripleo::profile::base::cinder::volume::cinder_enable_dellemc_xtremio_iscsi_backend: {get_param: CinderEnableDellEMCXTREMIOIscsiBackend}
-                cinder::backend::dellemc_xtremio_iscsi::volume_backend_name: {get_param: CinderDellEMCXTREMIOIscsiBackendName}
-                cinder::backend::dellemc_xtremio_iscsi::san_ip: {get_param: CinderDellEMCXTREMIOIscsiSanIp}
-                cinder::backend::dellemc_xtremio_iscsi::san_login: {get_param: CinderDellEMCXTREMIOIscsiSanLogin}
-                cinder::backend::dellemc_xtremio_iscsi::san_password: {get_param: CinderDellEMCXTREMIOIscsiSanPassword}
-                cinder::backend::dellemc_xtremio_iscsi::xtremio_cluster_name: {get_param: CinderDellEMCXTREMIOIscsiClusterName}
-                cinder::backend::dellemc_xtremio_iscsi::xtremio_array_busy_retry_count: {get_param: CinderDellEMCXTREMIOIscsiArrayBusyRetryCount}
-                cinder::backend::dellemc_xtremio_iscsi::xtremio_array_busy_retry_interval: {get_param: CinderDellEMCXTREMIOIscsiArrayBusyRetryInterval}
-                cinder::backend::dellemc_xtremio_iscsi::xtremio_volumes_per_glance_cache: {get_param: CinderDellEMCXTREMIOIscsiVolumesPerGlanceCache}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_dellemc_xtremio_iscsi_backend: {get_param: CinderEnableDellEMCXTREMIOIscsiBackend}
+            cinder::backend::dellemc_xtremio_iscsi::volume_backend_name: {get_param: CinderDellEMCXTREMIOIscsiBackendName}
+            cinder::backend::dellemc_xtremio_iscsi::san_ip: {get_param: CinderDellEMCXTREMIOIscsiSanIp}
+            cinder::backend::dellemc_xtremio_iscsi::san_login: {get_param: CinderDellEMCXTREMIOIscsiSanLogin}
+            cinder::backend::dellemc_xtremio_iscsi::san_password: {get_param: CinderDellEMCXTREMIOIscsiSanPassword}
+            cinder::backend::dellemc_xtremio_iscsi::xtremio_cluster_name: {get_param: CinderDellEMCXTREMIOIscsiClusterName}
+            cinder::backend::dellemc_xtremio_iscsi::xtremio_array_busy_retry_count: {get_param: CinderDellEMCXTREMIOIscsiArrayBusyRetryCount}
+            cinder::backend::dellemc_xtremio_iscsi::xtremio_array_busy_retry_interval: {get_param: CinderDellEMCXTREMIOIscsiArrayBusyRetryInterval}
+            cinder::backend::dellemc_xtremio_iscsi::xtremio_volumes_per_glance_cache: {get_param: CinderDellEMCXTREMIOIscsiVolumesPerGlanceCache}
+          -
+            if:
+            - {equals : [{get_param: CinderDellEMCXTREMIOIscsiAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::dellemc_xtremio_iscsi::backend_availability_zone: {get_param: CinderDellEMCXTREMIOIscsiAvailabilityZone}
diff --git a/puppet/services/cinder-backend-dellps.yaml b/puppet/services/cinder-backend-dellps.yaml
index ba9a3e3fc5..92d7a29ae9 100644
--- a/puppet/services/cinder-backend-dellps.yaml
+++ b/puppet/services/cinder-backend-dellps.yaml
@@ -24,6 +24,12 @@ parameters:
   CinderDellPsBackendName:
     type: string
     default: 'tripleo_dellps'
+  CinderDellPsAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Dell PS Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderDellPsSanIp:
     type: string
   CinderDellPsSanLogin:
@@ -85,15 +91,21 @@ outputs:
     value:
       service_name: cinder_backend_dellps
       config_settings:
-        tripleo::profile::base::cinder::volume::cinder_enable_dellps_backend: {get_param: CinderEnableDellPsBackend}
-        cinder::backend::eqlx::volume_backend_name: {get_param: CinderDellPsBackendName}
-        cinder::backend::eqlx::san_ip: {get_param: CinderDellPsSanIp}
-        cinder::backend::eqlx::san_login: {get_param: CinderDellPsSanLogin}
-        cinder::backend::eqlx::san_password: {get_param: CinderDellPsSanPassword}
-        cinder::backend::eqlx::san_private_key: {get_param: CinderDellPsSanPrivateKey}
-        cinder::backend::eqlx::san_thin_provision: {get_param: CinderDellPsSanThinProvision}
-        cinder::backend::eqlx::eqlx_group_name: {get_param: CinderDellPsGroupname}
-        cinder::backend::eqlx::eqlx_pool: {get_param: CinderDellPsPool}
-        cinder::backend::eqlx::eqlx_use_chap: {get_param: CinderDellPsUseChap}
-        cinder::backend::eqlx::eqlx_chap_login: {get_param: CinderDellPsChapLogin}
-        cinder::backend::eqlx::eqlx_chap_password: {get_param: CinderDellPsChapPassword}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_dellps_backend: {get_param: CinderEnableDellPsBackend}
+            cinder::backend::eqlx::volume_backend_name: {get_param: CinderDellPsBackendName}
+            cinder::backend::eqlx::san_ip: {get_param: CinderDellPsSanIp}
+            cinder::backend::eqlx::san_login: {get_param: CinderDellPsSanLogin}
+            cinder::backend::eqlx::san_password: {get_param: CinderDellPsSanPassword}
+            cinder::backend::eqlx::san_private_key: {get_param: CinderDellPsSanPrivateKey}
+            cinder::backend::eqlx::san_thin_provision: {get_param: CinderDellPsSanThinProvision}
+            cinder::backend::eqlx::eqlx_group_name: {get_param: CinderDellPsGroupname}
+            cinder::backend::eqlx::eqlx_pool: {get_param: CinderDellPsPool}
+            cinder::backend::eqlx::eqlx_use_chap: {get_param: CinderDellPsUseChap}
+            cinder::backend::eqlx::eqlx_chap_login: {get_param: CinderDellPsChapLogin}
+            cinder::backend::eqlx::eqlx_chap_password: {get_param: CinderDellPsChapPassword}
+          -
+            if:
+            - {equals : [{get_param: CinderDellPsAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::eqlx::backend_availability_zone: {get_param: CinderDellPsAvailabilityZone}
diff --git a/puppet/services/cinder-backend-dellsc.yaml b/puppet/services/cinder-backend-dellsc.yaml
index cc853264f6..a927c6310b 100644
--- a/puppet/services/cinder-backend-dellsc.yaml
+++ b/puppet/services/cinder-backend-dellsc.yaml
@@ -23,6 +23,12 @@ parameters:
   CinderDellScBackendName:
     type: string
     default: 'tripleo_dellsc'
+  CinderDellScAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Dell SC Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderDellScSanIp:
     type: string
   CinderDellScSanLogin:
@@ -105,20 +111,26 @@ outputs:
     value:
       service_name: cinder_backend_dellsc
       config_settings:
-                tripleo::profile::base::cinder::volume::cinder_enable_dellsc_backend: {get_param: CinderEnableDellScBackend}
-                cinder::backend::dellsc_iscsi::volume_backend_name: {get_param: CinderDellScBackendName}
-                cinder::backend::dellsc_iscsi::san_ip: {get_param: CinderDellScSanIp}
-                cinder::backend::dellsc_iscsi::san_login: {get_param: CinderDellScSanLogin}
-                cinder::backend::dellsc_iscsi::san_password: {get_param: CinderDellScSanPassword}
-                cinder::backend::dellsc_iscsi::dell_sc_ssn: {get_param: CinderDellScSsn}
-                cinder::backend::dellsc_iscsi::iscsi_ip_address: {get_param: CinderDellScIscsiIpAddress}
-                cinder::backend::dellsc_iscsi::iscsi_port: {get_param: CinderDellScIscsiPort}
-                cinder::backend::dellsc_iscsi::dell_sc_api_port: {get_param: CinderDellScApiPort}
-                cinder::backend::dellsc_iscsi::dell_sc_server_folder: {get_param: CinderDellScServerFolder}
-                cinder::backend::dellsc_iscsi::dell_sc_volume_folder: {get_param: CinderDellScVolumeFolder}
-                cinder::backend::dellsc_iscsi::secondary_san_ip: {get_param: CinderDellScSecondarySanIp}
-                cinder::backend::dellsc_iscsi::secondary_san_login: {get_param: CinderDellScSecondarySanLogin}
-                cinder::backend::dellsc_iscsi::secondary_san_password: {get_param: CinderDellScSecondarySanPassword}
-                cinder::backend::dellsc_iscsi::secondary_sc_api_port: {get_param: CinderDellScSecondaryScApiPort}
-                cinder::backend::dellsc_iscsi::excluded_domain_ips: {get_param: CinderDellScExcludedDomainIps}
-                cinder::backend::dellsc_iscsi::excluded_domain_ip: {get_param: CinderDellScExcludedDomainIp}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_dellsc_backend: {get_param: CinderEnableDellScBackend}
+            cinder::backend::dellsc_iscsi::volume_backend_name: {get_param: CinderDellScBackendName}
+            cinder::backend::dellsc_iscsi::san_ip: {get_param: CinderDellScSanIp}
+            cinder::backend::dellsc_iscsi::san_login: {get_param: CinderDellScSanLogin}
+            cinder::backend::dellsc_iscsi::san_password: {get_param: CinderDellScSanPassword}
+            cinder::backend::dellsc_iscsi::dell_sc_ssn: {get_param: CinderDellScSsn}
+            cinder::backend::dellsc_iscsi::iscsi_ip_address: {get_param: CinderDellScIscsiIpAddress}
+            cinder::backend::dellsc_iscsi::iscsi_port: {get_param: CinderDellScIscsiPort}
+            cinder::backend::dellsc_iscsi::dell_sc_api_port: {get_param: CinderDellScApiPort}
+            cinder::backend::dellsc_iscsi::dell_sc_server_folder: {get_param: CinderDellScServerFolder}
+            cinder::backend::dellsc_iscsi::dell_sc_volume_folder: {get_param: CinderDellScVolumeFolder}
+            cinder::backend::dellsc_iscsi::secondary_san_ip: {get_param: CinderDellScSecondarySanIp}
+            cinder::backend::dellsc_iscsi::secondary_san_login: {get_param: CinderDellScSecondarySanLogin}
+            cinder::backend::dellsc_iscsi::secondary_san_password: {get_param: CinderDellScSecondarySanPassword}
+            cinder::backend::dellsc_iscsi::secondary_sc_api_port: {get_param: CinderDellScSecondaryScApiPort}
+            cinder::backend::dellsc_iscsi::excluded_domain_ips: {get_param: CinderDellScExcludedDomainIps}
+            cinder::backend::dellsc_iscsi::excluded_domain_ip: {get_param: CinderDellScExcludedDomainIp}
+          -
+            if:
+            - {equals : [{get_param: CinderDellScAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::dellsc_iscsi::backend_availability_zone: {get_param: CinderDellScAvailabilityZone}
diff --git a/puppet/services/cinder-backend-netapp.yaml b/puppet/services/cinder-backend-netapp.yaml
index 7b67370c68..5a3cf5fbbc 100644
--- a/puppet/services/cinder-backend-netapp.yaml
+++ b/puppet/services/cinder-backend-netapp.yaml
@@ -35,6 +35,12 @@ parameters:
   CinderNetappBackendName:
     type: string
     default: 'tripleo_netapp'
+  CinderNetappAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the NetApp Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderNetappLogin:
     type: string
   CinderNetappPassword:
@@ -120,28 +126,34 @@ outputs:
     value:
       service_name: cinder_backend_netapp
       config_settings:
-        tripleo::profile::base::cinder::volume::cinder_enable_netapp_backend: {get_param: CinderEnableNetappBackend}
-        cinder::backend::netapp::volume_backend_name: {get_param: CinderNetappBackendName}
-        cinder::backend::netapp::netapp_login: {get_param: CinderNetappLogin}
-        cinder::backend::netapp::netapp_password: {get_param: CinderNetappPassword}
-        cinder::backend::netapp::netapp_server_hostname: {get_param: CinderNetappServerHostname}
-        cinder::backend::netapp::netapp_server_port: {get_param: CinderNetappServerPort}
-        cinder::backend::netapp::netapp_size_multiplier: {get_param: CinderNetappSizeMultiplier}
-        cinder::backend::netapp::netapp_storage_family: {get_param: CinderNetappStorageFamily}
-        cinder::backend::netapp::netapp_storage_protocol: {get_param: CinderNetappStorageProtocol}
-        cinder::backend::netapp::netapp_transport_type: {get_param: CinderNetappTransportType}
-        cinder::backend::netapp::netapp_vfiler: {get_param: CinderNetappVfiler}
-        cinder::backend::netapp::netapp_volume_list: {get_param: CinderNetappVolumeList}
-        cinder::backend::netapp::netapp_vserver: {get_param: CinderNetappVserver}
-        cinder::backend::netapp::netapp_partner_backend_name: {get_param: CinderNetappPartnerBackendName}
-        cinder::backend::netapp::nfs_shares: {get_param: CinderNetappNfsShares}
-        cinder::backend::netapp::nfs_shares_config: {get_param: CinderNetappNfsSharesConfig}
-        cinder::backend::netapp::nfs_mount_options: {get_param: CinderNetappNfsMountOptions}
-        cinder::backend::netapp::netapp_copyoffload_tool_path: {get_param: CinderNetappCopyOffloadToolPath}
-        cinder::backend::netapp::netapp_controller_ips: {get_param: CinderNetappControllerIps}
-        cinder::backend::netapp::netapp_sa_password: {get_param: CinderNetappSaPassword}
-        cinder::backend::netapp::netapp_storage_pools: {get_param: CinderNetappStoragePools}
-        cinder::backend::netapp::netapp_host_type: {get_param: CinderNetappHostType}
-        cinder::backend::netapp::netapp_webservice_path: {get_param: CinderNetappWebservicePath}
-        cinder::backend::netapp::nas_secure_file_operations: {get_param: CinderNetappNasSecureFileOperations}
-        cinder::backend::netapp::nas_secure_file_permissions: {get_param: CinderNetappNasSecureFilePermissions}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_netapp_backend: {get_param: CinderEnableNetappBackend}
+            cinder::backend::netapp::volume_backend_name: {get_param: CinderNetappBackendName}
+            cinder::backend::netapp::netapp_login: {get_param: CinderNetappLogin}
+            cinder::backend::netapp::netapp_password: {get_param: CinderNetappPassword}
+            cinder::backend::netapp::netapp_server_hostname: {get_param: CinderNetappServerHostname}
+            cinder::backend::netapp::netapp_server_port: {get_param: CinderNetappServerPort}
+            cinder::backend::netapp::netapp_size_multiplier: {get_param: CinderNetappSizeMultiplier}
+            cinder::backend::netapp::netapp_storage_family: {get_param: CinderNetappStorageFamily}
+            cinder::backend::netapp::netapp_storage_protocol: {get_param: CinderNetappStorageProtocol}
+            cinder::backend::netapp::netapp_transport_type: {get_param: CinderNetappTransportType}
+            cinder::backend::netapp::netapp_vfiler: {get_param: CinderNetappVfiler}
+            cinder::backend::netapp::netapp_volume_list: {get_param: CinderNetappVolumeList}
+            cinder::backend::netapp::netapp_vserver: {get_param: CinderNetappVserver}
+            cinder::backend::netapp::netapp_partner_backend_name: {get_param: CinderNetappPartnerBackendName}
+            cinder::backend::netapp::nfs_shares: {get_param: CinderNetappNfsShares}
+            cinder::backend::netapp::nfs_shares_config: {get_param: CinderNetappNfsSharesConfig}
+            cinder::backend::netapp::nfs_mount_options: {get_param: CinderNetappNfsMountOptions}
+            cinder::backend::netapp::netapp_copyoffload_tool_path: {get_param: CinderNetappCopyOffloadToolPath}
+            cinder::backend::netapp::netapp_controller_ips: {get_param: CinderNetappControllerIps}
+            cinder::backend::netapp::netapp_sa_password: {get_param: CinderNetappSaPassword}
+            cinder::backend::netapp::netapp_storage_pools: {get_param: CinderNetappStoragePools}
+            cinder::backend::netapp::netapp_host_type: {get_param: CinderNetappHostType}
+            cinder::backend::netapp::netapp_webservice_path: {get_param: CinderNetappWebservicePath}
+            cinder::backend::netapp::nas_secure_file_operations: {get_param: CinderNetappNasSecureFileOperations}
+            cinder::backend::netapp::nas_secure_file_permissions: {get_param: CinderNetappNasSecureFilePermissions}
+          -
+            if:
+            - {equals : [{get_param: CinderNetappAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::netapp::backend_availability_zone: {get_param: CinderNetappAvailabilityZone}
diff --git a/puppet/services/cinder-backend-nvmeof.yaml b/puppet/services/cinder-backend-nvmeof.yaml
index 743bf36d55..f45fc97ec8 100644
--- a/puppet/services/cinder-backend-nvmeof.yaml
+++ b/puppet/services/cinder-backend-nvmeof.yaml
@@ -7,6 +7,12 @@ parameters:
   CinderNVMeOFBackendName:
     type: string
     default: 'tripleo_nvmeof'
+  CinderNVMeOFAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the NVMeOF Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderNVMeOFTargetPort:
     type: number
     default: 4460
@@ -58,17 +64,23 @@ outputs:
     value:
       service_name: cinder_backend_nvmeof
       config_settings:
-        tripleo::profile::base::cinder::volume::cinder_enable_nvmeof_backend: true
-        tripleo::profile::base::cinder::volume::nvmeof::volume_backend_name: {get_param: CinderNVMeOFBackendName}
-        tripleo::profile::base::cinder::volume::nvmeof::target_port: {get_param: CinderNVMeOFTargetPort}
-        tripleo::profile::base::cinder::volume::nvmeof::target_helper: {get_param: CinderNVMeOFTargetHelper}
-        tripleo::profile::base::cinder::volume::nvmeof::target_protocol: {get_param: CinderNVMeOFTargetProtocol}
-        tripleo::profile::base::cinder::volume::nvmeof::target_prefix: {get_param: CinderNVMeOFTargetPrefix}
-        tripleo::profile::base::cinder::volume::nvmeof::nvmet_port_id: {get_param: CinderNVMeOFTargetPortId}
-        tripleo::profile::base::cinder::volume::nvmeof::nvmet_ns_id: {get_param: CinderNVMeOFTargetNameSpaceId}
-        tripleo::profile::base::cinder::volume::nvmeof::target_ip_address:
-          str_replace:
-            template:
-              "%{hiera('$NETWORK')}"
-            params:
-              $NETWORK: {get_param: [ServiceNetMap, CinderIscsiNetwork]}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_nvmeof_backend: true
+            tripleo::profile::base::cinder::volume::nvmeof::volume_backend_name: {get_param: CinderNVMeOFBackendName}
+            tripleo::profile::base::cinder::volume::nvmeof::target_port: {get_param: CinderNVMeOFTargetPort}
+            tripleo::profile::base::cinder::volume::nvmeof::target_helper: {get_param: CinderNVMeOFTargetHelper}
+            tripleo::profile::base::cinder::volume::nvmeof::target_protocol: {get_param: CinderNVMeOFTargetProtocol}
+            tripleo::profile::base::cinder::volume::nvmeof::target_prefix: {get_param: CinderNVMeOFTargetPrefix}
+            tripleo::profile::base::cinder::volume::nvmeof::nvmet_port_id: {get_param: CinderNVMeOFTargetPortId}
+            tripleo::profile::base::cinder::volume::nvmeof::nvmet_ns_id: {get_param: CinderNVMeOFTargetNameSpaceId}
+            tripleo::profile::base::cinder::volume::nvmeof::target_ip_address:
+              str_replace:
+                template:
+                  "%{hiera('$NETWORK')}"
+                params:
+                  $NETWORK: {get_param: [ServiceNetMap, CinderIscsiNetwork]}
+          -
+            if:
+            - {equals : [{get_param: CinderNVMeOFAvailabilityZone}, '']}
+            - {}
+            - tripleo::profile::base::cinder::volume::nvmeof::backend_availability_zone: {get_param: CinderNVMeOFAvailabilityZone}
diff --git a/puppet/services/cinder-backend-pure.yaml b/puppet/services/cinder-backend-pure.yaml
index e56de1727c..e869c93b97 100644
--- a/puppet/services/cinder-backend-pure.yaml
+++ b/puppet/services/cinder-backend-pure.yaml
@@ -49,6 +49,12 @@ parameters:
   CinderPureBackendName:
     type: string
     default: 'tripleo_pure'
+  CinderPureAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Pure Storage Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderPureStorageProtocol:
     type: string
     default: 'iSCSI'
@@ -69,10 +75,16 @@ outputs:
     value:
       service_name: cinder_backend_pure
       config_settings:
-                tripleo::profile::base::cinder::volume::cinder_enable_pure_backend: {get_param: CinderEnablePureBackend}
-                cinder::backend::pure::volume_backend_name: {get_param: CinderPureBackendName}
-                cinder::backend::pure::pure_storage_protocol: {get_param: CinderPureStorageProtocol}
-                cinder::backend::pure::san_ip: {get_param: CinderPureSanIp}
-                cinder::backend::pure::pure_api_token: {get_input: PureAPIToken}
-                cinder::backend::pure::use_chap_auth: {get_input: PureUseChap}
-                cinder::backend::pure::use_multipath_for_image_xfer: {get_input: PureMultipathXfer}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_pure_backend: {get_param: CinderEnablePureBackend}
+            cinder::backend::pure::volume_backend_name: {get_param: CinderPureBackendName}
+            cinder::backend::pure::pure_storage_protocol: {get_param: CinderPureStorageProtocol}
+            cinder::backend::pure::san_ip: {get_param: CinderPureSanIp}
+            cinder::backend::pure::pure_api_token: {get_input: PureAPIToken}
+            cinder::backend::pure::use_chap_auth: {get_input: PureUseChap}
+            cinder::backend::pure::use_multipath_for_image_xfer: {get_input: PureMultipathXfer}
+          -
+            if:
+            - {equals : [{get_param: CinderPureAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::pure::backend_availability_zone: {get_param: CinderPureAvailabilityZone}
diff --git a/puppet/services/cinder-backend-scaleio.yaml b/puppet/services/cinder-backend-scaleio.yaml
index 214fd096c3..c54f404fee 100644
--- a/puppet/services/cinder-backend-scaleio.yaml
+++ b/puppet/services/cinder-backend-scaleio.yaml
@@ -23,6 +23,12 @@ parameters:
   CinderScaleIOBackendName:
     type: string
     default: 'tripleo_scaleio'
+  CinderScaleIOAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the ScaleIO Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderScaleIOSanIp:
     type: string
     default: ''
@@ -102,20 +108,26 @@ outputs:
     value:
       service_name: cinder_backend_scaleio
       config_settings:
-        tripleo::profile::base::cinder::volume::cinder_enable_scaleio_backend: {get_param: CinderEnableScaleIOBackend}
-        cinder::backend::scaleio::volume_backend_name: {get_param: CinderScaleIOBackendName}
-        cinder::backend::scaleio::sio_login: {get_param: CinderScaleIOSanLogin}
-        cinder::backend::scaleio::sio_password: {get_param: CinderScaleIOSanPassword}
-        cinder::backend::scaleio::sio_server_hostname: {get_param: CinderScaleIOSanIp}
-        cinder::backend::scaleio::sio_server_port: {get_param: CinderScaleIORestServerPort}
-        cinder::backend::scaleio::sio_verify_server_certificate: {get_param: CinderScaleIOVerifyServerCertificate}
-        cinder::backend::scaleio::sio_server_certificate_path: {get_param: CinderScaleIOServerCertificatePath}
-        cinder::backend::scaleio::sio_protection_domain_name: {get_param: CinderScaleIOProtectionDomainName}
-        cinder::backend::scaleio::sio_protection_domain_id: {get_param: CinderScaleIOProtectionDomainId}
-        cinder::backend::scaleio::sio_storage_pool_id: {get_param: CinderScaleIOStoragePoolId}
-        cinder::backend::scaleio::sio_storage_pool_name: {get_param: CinderScaleIOStoragePoolName}
-        cinder::backend::scaleio::sio_storage_pools: {get_param: CinderScaleIOStoragePools}
-        cinder::backend::scaleio::sio_round_volume_capacity: {get_param: CinderScaleIORoundVolumeCapacity}
-        cinder::backend::scaleio::sio_unmap_volume_before_deletion: {get_param: CinderScaleIOUnmapVolumeBeforeDeletion}
-        cinder::backend::scaleio::sio_max_over_subscription_ratio: {get_param: CinderScaleIOMaxOverSubscriptionRatio}
-        cinder::backend::scaleio::sio_thin_provision: {get_param: CinderScaleIOSanThinProvision}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_scaleio_backend: {get_param: CinderEnableScaleIOBackend}
+            cinder::backend::scaleio::volume_backend_name: {get_param: CinderScaleIOBackendName}
+            cinder::backend::scaleio::sio_login: {get_param: CinderScaleIOSanLogin}
+            cinder::backend::scaleio::sio_password: {get_param: CinderScaleIOSanPassword}
+            cinder::backend::scaleio::sio_server_hostname: {get_param: CinderScaleIOSanIp}
+            cinder::backend::scaleio::sio_server_port: {get_param: CinderScaleIORestServerPort}
+            cinder::backend::scaleio::sio_verify_server_certificate: {get_param: CinderScaleIOVerifyServerCertificate}
+            cinder::backend::scaleio::sio_server_certificate_path: {get_param: CinderScaleIOServerCertificatePath}
+            cinder::backend::scaleio::sio_protection_domain_name: {get_param: CinderScaleIOProtectionDomainName}
+            cinder::backend::scaleio::sio_protection_domain_id: {get_param: CinderScaleIOProtectionDomainId}
+            cinder::backend::scaleio::sio_storage_pool_id: {get_param: CinderScaleIOStoragePoolId}
+            cinder::backend::scaleio::sio_storage_pool_name: {get_param: CinderScaleIOStoragePoolName}
+            cinder::backend::scaleio::sio_storage_pools: {get_param: CinderScaleIOStoragePools}
+            cinder::backend::scaleio::sio_round_volume_capacity: {get_param: CinderScaleIORoundVolumeCapacity}
+            cinder::backend::scaleio::sio_unmap_volume_before_deletion: {get_param: CinderScaleIOUnmapVolumeBeforeDeletion}
+            cinder::backend::scaleio::sio_max_over_subscription_ratio: {get_param: CinderScaleIOMaxOverSubscriptionRatio}
+            cinder::backend::scaleio::sio_thin_provision: {get_param: CinderScaleIOSanThinProvision}
+          -
+            if:
+            - {equals : [{get_param: CinderScaleIOAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::scaleio::backend_availability_zone: {get_param: CinderScaleIOAvailabilityZone}
diff --git a/puppet/services/cinder-backend-veritas-hyperscale.yaml b/puppet/services/cinder-backend-veritas-hyperscale.yaml
index 185bd0f559..c86bd33b49 100644
--- a/puppet/services/cinder-backend-veritas-hyperscale.yaml
+++ b/puppet/services/cinder-backend-veritas-hyperscale.yaml
@@ -17,6 +17,12 @@ description: >
   Openstack Veritas HyperScale backend
 
 parameters:
+  CinderVeritasHyperScaleAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Veritas HyperScale Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   ServiceData:
     default: {}
     description: Dictionary packing service data
@@ -51,4 +57,10 @@ outputs:
     value:
       service_name: cinder_backend_veritas_hyperscale
       config_settings:
-        tripleo::profile::base::cinder::volume::cinder_enable_vrts_hs_backend: true
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_vrts_hs_backend: true
+          -
+            if:
+            - {equals : [{get_param: CinderVeritasHyperScaleAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::veritas_hyperscale::backend_availability_zone: {get_param: CinderVeritasHyperScaleAvailabilityZone}
diff --git a/puppet/services/cinder-base.yaml b/puppet/services/cinder-base.yaml
index 0bac4dde01..5081a9bd28 100644
--- a/puppet/services/cinder-base.yaml
+++ b/puppet/services/cinder-base.yaml
@@ -4,6 +4,10 @@ description: >
   OpenStack Cinder base service. Shared by all Cinder services.
 
 parameters:
+  CinderStorageAvailabilityZone:
+    default: nova
+    description: The Cinder service's storage availability zone.
+    type: string
   CinderPassword:
     description: The password for the cinder service account, used by cinder-api.
     type: string
@@ -127,6 +131,7 @@ outputs:
           - service_debug_unset
           - {get_param: Debug }
           - {get_param: CinderDebug }
+        cinder::storage_availability_zone: {get_param: CinderStorageAvailabilityZone}
         cinder::rabbit_heartbeat_timeout_threshold: 60
         cinder::rabbit_userid: {get_param: RpcUserName}
         cinder::rabbit_password: {get_param: RpcPassword}
diff --git a/puppet/services/cinder-hpelefthand-iscsi.yaml b/puppet/services/cinder-hpelefthand-iscsi.yaml
index 39a7fa6b13..a31ff127fc 100644
--- a/puppet/services/cinder-hpelefthand-iscsi.yaml
+++ b/puppet/services/cinder-hpelefthand-iscsi.yaml
@@ -15,6 +15,12 @@ parameters:
   CinderHPELeftHandISCSIBackendName:
     type: string
     default: 'tripleo_hpelefthand'
+  CinderHPELeftHandISCSIAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the HPE LeftHand iSCSI Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderHPELeftHandISCSIChapEnabled:
     type: boolean
     default: false
@@ -56,11 +62,17 @@ outputs:
     value:
       service_name: cinder_hpelefthand_iscsi
       config_settings:
-        tripleo::profile::base::cinder::volume::cinder_enable_hpelefthand_backend: true
-        cinder::backend::hpelefthand_iscsi::hpelefthand_api_url: {get_param: CinderHPELeftHandISCSIApiUrl}
-        cinder::backend::hpelefthand_iscsi::hpelefthand_username: {get_param: CinderHPELeftHandISCSIUserName}
-        cinder::backend::hpelefthand_iscsi::hpelefthand_password: {get_param: CinderHPELeftHandISCSIPassword}
-        cinder::backend::hpelefthand_iscsi::volume_backend_name: {get_param: CinderHPELeftHandISCSIBackendName}
-        cinder::backend::hpelefthand_iscsi::hpelefthand_iscsi_chap_enabled: {get_param: CinderHPELeftHandISCSIChapEnabled}
-        cinder::backend::hpelefthand_iscsi::hpelefthand_clustername: {get_param: CinderHPELeftHandClusterName}
-        cinder::backend::hpelefthand_iscsi::hpelefthand_debug: {get_param: CinderHPELeftHandDebug}
+        map_merge:
+          - tripleo::profile::base::cinder::volume::cinder_enable_hpelefthand_backend: true
+            cinder::backend::hpelefthand_iscsi::hpelefthand_api_url: {get_param: CinderHPELeftHandISCSIApiUrl}
+            cinder::backend::hpelefthand_iscsi::hpelefthand_username: {get_param: CinderHPELeftHandISCSIUserName}
+            cinder::backend::hpelefthand_iscsi::hpelefthand_password: {get_param: CinderHPELeftHandISCSIPassword}
+            cinder::backend::hpelefthand_iscsi::volume_backend_name: {get_param: CinderHPELeftHandISCSIBackendName}
+            cinder::backend::hpelefthand_iscsi::hpelefthand_iscsi_chap_enabled: {get_param: CinderHPELeftHandISCSIChapEnabled}
+            cinder::backend::hpelefthand_iscsi::hpelefthand_clustername: {get_param: CinderHPELeftHandClusterName}
+            cinder::backend::hpelefthand_iscsi::hpelefthand_debug: {get_param: CinderHPELeftHandDebug}
+          -
+            if:
+            - {equals : [{get_param: CinderHPELeftHandISCSIAvailabilityZone}, '']}
+            - {}
+            - cinder::backend::hpelefthand_iscsi::backend_availability_zone: {get_param: CinderHPELeftHandISCSIAvailabilityZone}
diff --git a/puppet/services/cinder-volume.yaml b/puppet/services/cinder-volume.yaml
index d021b449ac..42248a1008 100644
--- a/puppet/services/cinder-volume.yaml
+++ b/puppet/services/cinder-volume.yaml
@@ -16,6 +16,12 @@ parameters:
     default: false
     description: Whether to enable or not the Rbd backend for Cinder
     type: boolean
+  CinderISCSIAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the Iscsi Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderISCSIHelper:
     default: lioadm
     description: The iSCSI helper to use with cinder.
@@ -28,6 +34,12 @@ parameters:
     default: 10280
     description: The size of the loopback file used by the cinder LVM driver.
     type: number
+  CinderNfsAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the NFS Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderNfsMountOptions:
     default: ''
     description: >
@@ -54,6 +66,12 @@ parameters:
       Valid values are 'auto', 'true' or 'false'. Effective when
       CinderEnableNfsBackend is true.
     type: string
+  CinderRbdAvailabilityZone:
+    default: ''
+    description: >
+      The availability zone of the RBD Cinder backend.
+      When set, it overrides the default CinderStorageAvailabilityZone.
+    type: string
   CinderRbdPoolName:
     default: volumes
     type: string
@@ -170,6 +188,21 @@ outputs:
                   "%{hiera('$NETWORK')}"
                 params:
                   $NETWORK: {get_param: [ServiceNetMap, CinderIscsiNetwork]}
+          -
+            if:
+            - {equals : [{get_param: CinderISCSIAvailabilityZone}, '']}
+            - {}
+            - tripleo::profile::base::cinder::volume::iscsi::backend_availability_zone: {get_param: CinderISCSIAvailabilityZone}
+          -
+            if:
+            - {equals : [{get_param: CinderNfsAvailabilityZone}, '']}
+            - {}
+            - tripleo::profile::base::cinder::volume::nfs::backend_availability_zone: {get_param: CinderNfsAvailabilityZone}
+          -
+            if:
+            - {equals : [{get_param: CinderRbdAvailabilityZone}, '']}
+            - {}
+            - tripleo::profile::base::cinder::volume::rbd::backend_availability_zone: {get_param: CinderRbdAvailabilityZone}
       service_config_settings:
         fluentd:
           tripleo_fluentd_groups_cinder_volume:
diff --git a/releasenotes/notes/add-cinder-storage-az-parameters-cddf410bc3464193.yaml b/releasenotes/notes/add-cinder-storage-az-parameters-cddf410bc3464193.yaml
new file mode 100644
index 0000000000..b326fe3de0
--- /dev/null
+++ b/releasenotes/notes/add-cinder-storage-az-parameters-cddf410bc3464193.yaml
@@ -0,0 +1,11 @@
+---
+features:
+  - |
+    Add CinderStorageAvailabilityZone parameter that configures
+    cinder's DEFAULT/storage_availability_zone. The default value
+    of 'nova' matches cinder's own default value.
+
+    Add several CinderXXXAvailabilityZone parameters, where XXX is
+    any of the cinder volume service's storage backends. The
+    parameters are optional, and when set they override the
+    "backend_availability_zone" for the corresponding backend.