diff --git a/etcdserver/api/v3rpc/maintenance.go b/etcdserver/api/v3rpc/maintenance.go
index a64ac2636..7f08b0b91 100644
--- a/etcdserver/api/v3rpc/maintenance.go
+++ b/etcdserver/api/v3rpc/maintenance.go
@@ -60,7 +60,7 @@ func (ms *maintenanceServer) Defragment(ctx context.Context, sr *pb.DefragmentRe
 	plog.Noticef("starting to defragment the storage backend...")
 	err := ms.bg.Backend().Defrag()
 	if err != nil {
-		plog.Errorf("failed to deframent the storage backend (%v)", err)
+		plog.Errorf("failed to defragment the storage backend (%v)", err)
 		return nil, err
 	}
 	plog.Noticef("finished defragmenting the storage backend")
diff --git a/mvcc/backend/batch_tx.go b/mvcc/backend/batch_tx.go
index 08a0e5449..885402f22 100644
--- a/mvcc/backend/batch_tx.go
+++ b/mvcc/backend/batch_tx.go
@@ -52,7 +52,7 @@ func newBatchTx(backend *backend) *batchTx {
 func (t *batchTx) UnsafeCreateBucket(name []byte) {
 	_, err := t.tx.CreateBucket(name)
 	if err != nil && err != bolt.ErrBucketExists {
-		log.Fatalf("mvcc: cannot create bucket %s (%v)", string(name), err)
+		log.Fatalf("mvcc: cannot create bucket %s (%v)", name, err)
 	}
 	t.pending++
 }
@@ -70,7 +70,7 @@ func (t *batchTx) UnsafeSeqPut(bucketName []byte, key []byte, value []byte) {
 func (t *batchTx) unsafePut(bucketName []byte, key []byte, value []byte, seq bool) {
 	bucket := t.tx.Bucket(bucketName)
 	if bucket == nil {
-		log.Fatalf("mvcc: bucket %s does not exist", string(bucketName))
+		log.Fatalf("mvcc: bucket %s does not exist", bucketName)
 	}
 	if seq {
 		// it is useful to increase fill percent when the workloads are mostly append-only.
@@ -87,7 +87,7 @@ func (t *batchTx) unsafePut(bucketName []byte, key []byte, value []byte, seq boo
 func (t *batchTx) UnsafeRange(bucketName []byte, key, endKey []byte, limit int64) (keys [][]byte, vs [][]byte) {
 	bucket := t.tx.Bucket(bucketName)
 	if bucket == nil {
-		log.Fatalf("mvcc: bucket %s does not exist", string(bucketName))
+		log.Fatalf("mvcc: bucket %s does not exist", bucketName)
 	}
 
 	if len(endKey) == 0 {
@@ -114,7 +114,7 @@ func (t *batchTx) UnsafeRange(bucketName []byte, key, endKey []byte, limit int64
 func (t *batchTx) UnsafeDelete(bucketName []byte, key []byte) {
 	bucket := t.tx.Bucket(bucketName)
 	if bucket == nil {
-		log.Fatalf("mvcc: bucket %s does not exist", string(bucketName))
+		log.Fatalf("mvcc: bucket %s does not exist", bucketName)
 	}
 	err := bucket.Delete(key)
 	if err != nil {
diff --git a/mvcc/key_index.go b/mvcc/key_index.go
index c2b2aeee1..8f121874c 100644
--- a/mvcc/key_index.go
+++ b/mvcc/key_index.go
@@ -24,7 +24,7 @@ import (
 )
 
 var (
-	ErrRevisionNotFound = errors.New("stroage: revision not found")
+	ErrRevisionNotFound = errors.New("mvcc: revision not found")
 )
 
 // keyIndex stores the revisions of a key in the backend.