diff --git a/pkg/backend/aio.go b/pkg/backend/aio.go
index e3f3ba57..6d539e44 100644
--- a/pkg/backend/aio.go
+++ b/pkg/backend/aio.go
@@ -65,7 +65,7 @@ func (s *Server) DeleteAioController(_ context.Context, in *pb.DeleteAioControll
 		if in.AllowMissing {
 			return &emptypb.Empty{}, nil
 		}
-		err := fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
 		log.Printf("error: %v", err)
 		return nil, err
 	}
diff --git a/pkg/backend/aio_test.go b/pkg/backend/aio_test.go
index 2ab2b567..cb88d530 100644
--- a/pkg/backend/aio_test.go
+++ b/pkg/backend/aio_test.go
@@ -659,7 +659,7 @@ func TestBackEnd_DeleteAioController(t *testing.T) {
 			"unknown-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-id"),
 			false,
 			false,
diff --git a/pkg/backend/null.go b/pkg/backend/null.go
index d96e16b7..82d767c0 100644
--- a/pkg/backend/null.go
+++ b/pkg/backend/null.go
@@ -65,7 +65,7 @@ func (s *Server) DeleteNullDebug(_ context.Context, in *pb.DeleteNullDebugReques
 		if in.AllowMissing {
 			return &emptypb.Empty{}, nil
 		}
-		err := fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
 		log.Printf("error: %v", err)
 		return nil, err
 	}
diff --git a/pkg/backend/null_test.go b/pkg/backend/null_test.go
index a079aff7..50167dce 100644
--- a/pkg/backend/null_test.go
+++ b/pkg/backend/null_test.go
@@ -668,7 +668,7 @@ func TestBackEnd_DeleteNullDebug(t *testing.T) {
 			"unknown-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-id"),
 			false,
 			false,
diff --git a/pkg/backend/nvme.go b/pkg/backend/nvme.go
index bf4e28a7..f0a158a2 100644
--- a/pkg/backend/nvme.go
+++ b/pkg/backend/nvme.go
@@ -68,7 +68,7 @@ func (s *Server) DeleteNVMfRemoteController(_ context.Context, in *pb.DeleteNVMf
 		if in.AllowMissing {
 			return &emptypb.Empty{}, nil
 		}
-		err := fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
 		log.Printf("error: %v -> %v", err, volume)
 		// return nil, err
 	}
diff --git a/pkg/frontend/blk.go b/pkg/frontend/blk.go
index 5f1cf5f2..aeeba694 100644
--- a/pkg/frontend/blk.go
+++ b/pkg/frontend/blk.go
@@ -65,7 +65,9 @@ func (s *Server) DeleteVirtioBlk(_ context.Context, in *pb.DeleteVirtioBlkReques
 		if in.AllowMissing {
 			return &emptypb.Empty{}, nil
 		}
-		return nil, fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
+		log.Printf("error: %v", err)
+		return nil, err
 	}
 	params := models.VhostDeleteControllerParams{
 		Ctrlr: in.Name,
diff --git a/pkg/frontend/blk_test.go b/pkg/frontend/blk_test.go
index b8529e78..1d74b9f5 100644
--- a/pkg/frontend/blk_test.go
+++ b/pkg/frontend/blk_test.go
@@ -494,7 +494,7 @@ func TestFrontEnd_DeleteVirtioBlk(t *testing.T) {
 			"unknown-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-id"),
 			false,
 			false,
diff --git a/pkg/frontend/nvme.go b/pkg/frontend/nvme.go
index 2579eb62..86f051d0 100644
--- a/pkg/frontend/nvme.go
+++ b/pkg/frontend/nvme.go
@@ -128,7 +128,7 @@ func (s *Server) DeleteNVMeSubsystem(_ context.Context, in *pb.DeleteNVMeSubsyst
 		if in.AllowMissing {
 			return &emptypb.Empty{}, nil
 		}
-		err := fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
 		log.Printf("error: %v", err)
 		return nil, err
 	}
@@ -184,7 +184,7 @@ func (s *Server) GetNVMeSubsystem(_ context.Context, in *pb.GetNVMeSubsystemRequ
 	log.Printf("GetNVMeSubsystem: Received from client: %v", in)
 	subsys, ok := s.Nvme.Subsystems[in.Name]
 	if !ok {
-		err := fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
 		log.Printf("error: %v", err)
 		return nil, err
 	}
@@ -271,7 +271,9 @@ func (s *Server) DeleteNVMeController(_ context.Context, in *pb.DeleteNVMeContro
 		if in.AllowMissing {
 			return &emptypb.Empty{}, nil
 		}
-		return nil, fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
+		log.Printf("error: %v", err)
+		return nil, err
 	}
 	subsys, ok := s.Nvme.Subsystems[controller.Spec.SubsystemId.Value]
 	if !ok {
@@ -326,7 +328,9 @@ func (s *Server) GetNVMeController(_ context.Context, in *pb.GetNVMeControllerRe
 	log.Printf("Received from client: %v", in.Name)
 	controller, ok := s.Nvme.Controllers[in.Name]
 	if !ok {
-		return nil, fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
+		log.Printf("error: %v", err)
+		return nil, err
 	}
 	return &pb.NVMeController{Spec: &pb.NVMeControllerSpec{Id: &pc.ObjectKey{Value: in.Name}, NvmeControllerId: controller.Spec.NvmeControllerId}, Status: &pb.NVMeControllerStatus{Active: true}}, nil
 }
@@ -394,7 +398,7 @@ func (s *Server) DeleteNVMeNamespace(_ context.Context, in *pb.DeleteNVMeNamespa
 		if in.AllowMissing {
 			return &emptypb.Empty{}, nil
 		}
-		err := fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
 		log.Printf("error: %v", err)
 		return nil, err
 	}
@@ -488,7 +492,7 @@ func (s *Server) GetNVMeNamespace(_ context.Context, in *pb.GetNVMeNamespaceRequ
 	log.Printf("GetNVMeNamespace: Received from client: %v", in)
 	namespace, ok := s.Nvme.Namespaces[in.Name]
 	if !ok {
-		err := fmt.Errorf("unable to find key %s", in.Name)
+		err := status.Errorf(codes.NotFound, "unable to find key %s", in.Name)
 		log.Printf("error: %v", err)
 		return nil, err
 	}
diff --git a/pkg/frontend/nvme_test.go b/pkg/frontend/nvme_test.go
index 949b09a7..8d4d8e70 100644
--- a/pkg/frontend/nvme_test.go
+++ b/pkg/frontend/nvme_test.go
@@ -422,7 +422,7 @@ func TestFrontEnd_GetNVMeSubsystem(t *testing.T) {
 			"unknown-subsystem-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-subsystem-id"),
 			false,
 		},
@@ -850,7 +850,7 @@ func TestFrontEnd_GetNVMeController(t *testing.T) {
 			"unknown-controller-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %s", "unknown-controller-id"),
 			false,
 		},
@@ -1385,7 +1385,7 @@ func TestFrontEnd_GetNVMeNamespace(t *testing.T) {
 			"unknown-namespace-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-namespace-id"),
 			false,
 		},
@@ -1543,7 +1543,7 @@ func TestFrontEnd_DeleteNVMeNamespace(t *testing.T) {
 			"unknown-namespace-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-namespace-id"),
 			false,
 			false,
@@ -1654,7 +1654,7 @@ func TestFrontEnd_DeleteNVMeController(t *testing.T) {
 			"unknown-controller-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-controller-id"),
 			false,
 			false,
@@ -1764,7 +1764,7 @@ func TestFrontEnd_DeleteNVMeSubsystem(t *testing.T) {
 			"unknown-subsystem-id",
 			nil,
 			[]string{""},
-			codes.Unknown,
+			codes.NotFound,
 			fmt.Sprintf("unable to find key %v", "unknown-subsystem-id"),
 			false,
 			false,