diff --git a/pkg/cephfs/util.go b/pkg/cephfs/util.go
index 8b4426958d49..333e237cc9f1 100644
--- a/pkg/cephfs/util.go
+++ b/pkg/cephfs/util.go
@@ -109,12 +109,12 @@ func (cs *ControllerServer) validateCreateVolumeRequest(req *csi.CreateVolumeReq
 	}
 
 	if req.GetName() == "" {
-		return status.Error(codes.InvalidArgument, "Volume Name cannot be empty")
+		return status.Error(codes.InvalidArgument, "volume Name cannot be empty")
 	}
 
 	reqCaps := req.GetVolumeCapabilities()
 	if reqCaps == nil {
-		return status.Error(codes.InvalidArgument, "Volume Capabilities cannot be empty")
+		return status.Error(codes.InvalidArgument, "volume Capabilities cannot be empty")
 	}
 
 	for _, cap := range reqCaps {
diff --git a/pkg/rbd/controllerserver.go b/pkg/rbd/controllerserver.go
index 3beb87d75453..0d477ea1aec3 100644
--- a/pkg/rbd/controllerserver.go
+++ b/pkg/rbd/controllerserver.go
@@ -82,10 +82,10 @@ func (cs *ControllerServer) validateVolumeReq(req *csi.CreateVolumeRequest) erro
 	}
 	// Check sanity of request Name, Volume Capabilities
 	if len(req.Name) == 0 {
-		return status.Error(codes.InvalidArgument, "Volume Name cannot be empty")
+		return status.Error(codes.InvalidArgument, "volume Name cannot be empty")
 	}
 	if req.VolumeCapabilities == nil {
-		return status.Error(codes.InvalidArgument, "Volume Capabilities cannot be empty")
+		return status.Error(codes.InvalidArgument, "volume Capabilities cannot be empty")
 	}
 	return nil
 }
@@ -177,7 +177,7 @@ func (cs *ControllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 				},
 			}, nil
 		}
-		return nil, status.Errorf(codes.AlreadyExists, "Volume with the same name: %s but with different size already exist", req.GetName())
+		return nil, status.Errorf(codes.AlreadyExists, "volume with the same name: %s but with different size already exist", req.GetName())
 	}
 
 	rbdVol, err := parseVolCreateRequest(req)
@@ -235,12 +235,12 @@ func (cs *ControllerServer) checkRBDStatus(rbdVol *rbdVolume, req *csi.CreateVol
 func (cs *ControllerServer) checkSnapshot(req *csi.CreateVolumeRequest, rbdVol *rbdVolume) error {
 	snapshot := req.VolumeContentSource.GetSnapshot()
 	if snapshot == nil {
-		return status.Error(codes.InvalidArgument, "Volume Snapshot cannot be empty")
+		return status.Error(codes.InvalidArgument, "volume Snapshot cannot be empty")
 	}
 
 	snapshotID := snapshot.GetSnapshotId()
 	if len(snapshotID) == 0 {
-		return status.Error(codes.InvalidArgument, "Volume Snapshot ID cannot be empty")
+		return status.Error(codes.InvalidArgument, "volume Snapshot ID cannot be empty")
 	}
 
 	rbdSnap := &rbdSnapshot{}
@@ -400,7 +400,7 @@ func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateS
 				},
 			}, nil
 		}
-		return nil, status.Errorf(codes.AlreadyExists, "Snapshot with the same name: %s but with different source volume id already exist", req.GetName())
+		return nil, status.Errorf(codes.AlreadyExists, "snapshot with the same name: %s but with different source volume id already exist", req.GetName())
 	}
 
 	rbdSnap, err := getRBDSnapshotOptions(req.GetParameters())
@@ -413,7 +413,7 @@ func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateS
 	uniqueID := uuid.NewUUID().String()
 	rbdVolume, err := getRBDVolumeByID(req.GetSourceVolumeId())
 	if err != nil {
-		return nil, status.Errorf(codes.NotFound, "Source Volume ID %s cannot found", req.GetSourceVolumeId())
+		return nil, status.Errorf(codes.NotFound, "source Volume ID %s cannot found", req.GetSourceVolumeId())
 	}
 	if !hasSnapshotFeature(rbdVolume.ImageFeatures) {
 		return nil, status.Errorf(codes.InvalidArgument, "volume(%s) has not snapshot feature(layering)", req.GetSourceVolumeId())
@@ -470,10 +470,10 @@ func (cs *ControllerServer) validateSnapshotReq(req *csi.CreateSnapshotRequest)
 
 	// Check sanity of request Snapshot Name, Source Volume Id
 	if len(req.Name) == 0 {
-		return status.Error(codes.InvalidArgument, "Snapshot Name cannot be empty")
+		return status.Error(codes.InvalidArgument, "snapshot Name cannot be empty")
 	}
 	if len(req.SourceVolumeId) == 0 {
-		return status.Error(codes.InvalidArgument, "Source Volume ID cannot be empty")
+		return status.Error(codes.InvalidArgument, "source Volume ID cannot be empty")
 	}
 	return nil
 }
@@ -523,7 +523,7 @@ func (cs *ControllerServer) DeleteSnapshot(ctx context.Context, req *csi.DeleteS
 
 	snapshotID := req.GetSnapshotId()
 	if len(snapshotID) == 0 {
-		return nil, status.Error(codes.InvalidArgument, "Snapshot ID cannot be empty")
+		return nil, status.Error(codes.InvalidArgument, "snapshot ID cannot be empty")
 	}
 	snapshotIDMutex.LockKey(snapshotID)
 
@@ -581,7 +581,7 @@ func (cs *ControllerServer) ListSnapshots(ctx context.Context, req *csi.ListSnap
 		if rbdSnap, ok := rbdSnapshots[snapshotID]; ok {
 			// if source volume ID also set, check source volume id on the cache.
 			if len(sourceVolumeID) != 0 && rbdSnap.SourceVolumeID != sourceVolumeID {
-				return nil, status.Errorf(codes.Unknown, "Requested Source Volume ID %s is different from %s", sourceVolumeID, rbdSnap.SourceVolumeID)
+				return nil, status.Errorf(codes.Unknown, "requested Source Volume ID %s is different from %s", sourceVolumeID, rbdSnap.SourceVolumeID)
 			}
 			return &csi.ListSnapshotsResponse{
 				Entries: []*csi.ListSnapshotsResponse_Entry{
@@ -599,7 +599,7 @@ func (cs *ControllerServer) ListSnapshots(ctx context.Context, req *csi.ListSnap
 				},
 			}, nil
 		}
-		return nil, status.Errorf(codes.NotFound, "Snapshot ID %s cannot found", snapshotID)
+		return nil, status.Errorf(codes.NotFound, "snapshot ID %s cannot found", snapshotID)
 
 	}
 
diff --git a/pkg/rbd/nodeserver.go b/pkg/rbd/nodeserver.go
index 5b5cffaf728e..0ce9072fc6ad 100644
--- a/pkg/rbd/nodeserver.go
+++ b/pkg/rbd/nodeserver.go
@@ -23,7 +23,7 @@ import (
 	"regexp"
 	"strings"
 
-	"github.com/ceph/ceph-csi/pkg/csi-common"
+	csicommon "github.com/ceph/ceph-csi/pkg/csi-common"
 
 	"github.com/container-storage-interface/spec/lib/go/csi"
 	"golang.org/x/net/context"
@@ -207,7 +207,7 @@ func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpu
 	if notMnt {
 		// TODO should consider deleting path instead of returning error,
 		// once all codes become ready for csi 1.0.
-		return nil, status.Error(codes.NotFound, "Volume not mounted")
+		return nil, status.Error(codes.NotFound, "volume not mounted")
 	}
 
 	devicePath, cnt, err := mount.GetDeviceNameFromMount(ns.mounter, targetPath)