diff --git a/app/models/transformation_mapping_item.rb b/app/models/transformation_mapping_item.rb
index 6186119f673..8e57c5e7e98 100644
--- a/app/models/transformation_mapping_item.rb
+++ b/app/models/transformation_mapping_item.rb
@@ -3,25 +3,56 @@ class TransformationMappingItem < ApplicationRecord
   belongs_to :source,      :polymorphic => true
   belongs_to :destination, :polymorphic => true
 
-  validates :source_id, :uniqueness => {:scope => [:transformation_mapping_id, :source_type]}
+  validates :source_id, :uniqueness => {:scope => [:transformation_mapping_id, :source_type, :destination_type]}
 
-  validate :source_cluster,      :if => -> { source.kind_of?(EmsCluster) }
-  validate :destination_cluster, :if => -> { destination.kind_of?(EmsCluster) || destination.kind_of?(CloudTenant) }
+  validate :validate_source_cluster,      :if => -> { source.kind_of?(EmsCluster) }
+  validate :validate_destination_cluster, :if => -> { destination.kind_of?(EmsCluster) || destination.kind_of?(CloudTenant) }
+
+  validate :validate_source_datastore,      :if => -> { source.kind_of?(Storage) }
+  validate :validate_destination_datastore, :if => -> { destination.kind_of?(Storage) || destination.kind_of?(CloudVolume) }
 
   VALID_SOURCE_CLUSTER_PROVIDERS = %w[vmwarews].freeze
   VALID_DESTINATION_CLUSTER_PROVIDERS = %w[rhevm openstack].freeze
 
-  def source_cluster
+  def validate_source_cluster
     unless VALID_SOURCE_CLUSTER_PROVIDERS.include?(source.ext_management_system.emstype)
       source_types = VALID_SOURCE_CLUSTER_PROVIDERS.join(', ')
       errors.add(:source, "EMS type of source cluster must be in: #{source_types}")
     end
   end
 
-  def destination_cluster
+  def validate_destination_cluster
     unless VALID_DESTINATION_CLUSTER_PROVIDERS.include?(destination.ext_management_system.emstype)
       destination_types = VALID_DESTINATION_CLUSTER_PROVIDERS.join(', ')
       errors.add(:destination, "EMS type of destination cluster or cloud tenant must be in: #{destination_types}")
     end
   end
+
+  def validate_source_datastore
+    tm                   = transformation_mapping
+    tmis                 = tm.transformation_mapping_items.where(:source_type => "EmsCluster")
+    src_cluster_storages = tmis.collect(&:source).flat_map(&:storages)
+    source_storage       = source
+
+    unless src_cluster_storages.include?(source_storage)
+      errors.add(:source, "Source cluster storages must include source storage: #{source_storage}")
+    end
+  end
+
+  def validate_destination_datastore
+    tm                  = transformation_mapping
+    destination_storage = destination
+
+    if destination.kind_of?(Storage) # red hat
+      tmis                 = tm.transformation_mapping_items.where(:destination_type=> "EmsCluster")
+      dst_cluster_storages = tmis.collect(&:destination).flat_map(&:storages)
+    elsif destination.kind_of?(CloudVolume) # Openstack
+      tmis                 = tm.transformation_mapping_items.where(:destination_type => "CloudTenant")
+      dst_cluster_storages = tmis.collect(&:destination).flat_map(&:cloud_volumes)
+    end
+
+    unless dst_cluster_storages.include?(destination_storage)
+      errors.add(:destination, "Destination cluster storages must include destination storage: #{destination_storage}")
+    end
+  end
 end
diff --git a/spec/models/transformation_mapping_item_spec.rb b/spec/models/transformation_mapping_item_spec.rb
index 8571dc8c022..a2df80dcac9 100644
--- a/spec/models/transformation_mapping_item_spec.rb
+++ b/spec/models/transformation_mapping_item_spec.rb
@@ -45,4 +45,59 @@
       expect(invalid_mapping_item.errors[:destination].first).to match("EMS type of destination cluster or cloud tenant must be in")
     end
   end
+
+  context "datastore validation" do
+    let(:ems_vmware) { FactoryBot.create(:ems_vmware) }
+    let(:vmware_cluster) { FactoryBot.create(:ems_cluster, :ext_management_system => ems_vmware) }
+
+    let(:ems_redhat) { FactoryBot.create(:ems_redhat) }
+    let(:redhat_cluster) { FactoryBot.create(:ems_cluster, :ext_management_system => ems_redhat) }
+
+    let(:ems_ops) { FactoryBot.create(:ems_openstack) }
+    let(:cloud_tenant) { FactoryBot.create(:cloud_tenant_openstack, :ext_management_system => ems_ops) }
+
+    context "source vmware datastore" do
+      let(:src_vmware_host) { FactoryBot.create(:host_vmware, :ems_cluster => vmware_cluster) }
+      let(:src_storage) { FactoryBot.create(:storage_vmware, :hosts => [src_vmware_host]) }
+
+      context "destination openstack" do
+        let(:disk) { FactoryBot.create(:disk) }
+        let(:cloud_volume_openstack) { FactoryBot.create(:cloud_volume_openstack, :attachments => [disk], :cloud_tenant => cloud_tenant) }
+
+        let(:tmi_ops_cluster) { FactoryBot.create(:transformation_mapping_item, :source => vmware_cluster, :destination => cloud_tenant) }
+        let(:ops_mapping) { FactoryBot.create(:transformation_mapping, :transformation_mapping_items => [tmi_ops_cluster]) }
+
+        let(:valid_source) { FactoryBot.create(:transformation_mapping_item, :source => src_storage, :destination => cloud_volume_openstack, :transformation_mapping_id => ops_mapping.id) }
+        let(:invalid_source) { FactoryBot.build(:transformation_mapping_item, :source => cloud_volume_openstack, :destination => src_storage, :transformation_mapping_id => ops_mapping.id) }
+
+        it "valid source" do
+          expect(valid_source.valid?).to be(true)
+        end
+        it "invalid source" do
+          expect(invalid_source.valid?).to be(false)
+        end
+      end
+
+      context "destination red hat" do
+        let(:dst_redhat_host) { FactoryBot.create(:host_redhat, :ems_cluster => redhat_cluster) }
+        let(:dst_storage) { FactoryBot.create(:storage_nfs, :hosts => [dst_redhat_host]) }
+
+        let(:tmi_cluster) { FactoryBot.create(:transformation_mapping_item, :source => vmware_cluster, :destination => redhat_cluster) }
+
+        let(:rh_mapping) { FactoryBot.create(:transformation_mapping, :transformation_mapping_items => [tmi_cluster]) }
+
+        context "source validation" do
+          let(:valid_storage) { FactoryBot.create(:transformation_mapping_item, :source => src_storage, :destination => dst_storage, :transformation_mapping_id => rh_mapping.id) }
+          let(:invalid_storage) { FactoryBot.build(:transformation_mapping_item, :source => dst_storage, :destination => src_storage, :transformation_mapping_id => rh_mapping.id) }
+
+          it "validate rhev destination" do
+            expect(valid_storage.valid?).to be(true)
+          end
+          it "invalidate badrhev destination" do
+            expect(invalid_storage.valid?).to be(false)
+          end
+        end
+      end
+    end
+  end
 end