diff --git a/internal/metarepos/raft_test.go b/internal/metarepos/raft_test.go
index 2bfadfbcc..2ca8b3c60 100644
--- a/internal/metarepos/raft_test.go
+++ b/internal/metarepos/raft_test.go
@@ -10,6 +10,7 @@ import (
 
 	. "github.com/smartystreets/goconvey/convey"
 	"go.etcd.io/etcd/raft/raftpb"
+	"go.uber.org/multierr"
 	"go.uber.org/zap"
 
 	"github.com/kakao/varlog/pkg/types"
@@ -129,13 +130,13 @@ func (clus *cluster) close(i int) (err error) {
 func (clus *cluster) Close() (err error) {
 	for i := range clus.peers {
 		if erri := clus.close(i); erri != nil {
-			err = erri
+			err = multierr.Append(err, erri)
 		}
 	}
 
 	os.RemoveAll("raftdata") //nolint:errcheck,revive // TODO:: Handle an error returned.
 
-	return clus.portLease.Release()
+	return multierr.Append(err, clus.portLease.Release())
 }
 
 func (clus *cluster) closeNoErrors(t *testing.T) {
diff --git a/internal/storagenode/logstream/replicate_task.go b/internal/storagenode/logstream/replicate_task.go
index 052c45f02..1bcddc619 100644
--- a/internal/storagenode/logstream/replicate_task.go
+++ b/internal/storagenode/logstream/replicate_task.go
@@ -91,5 +91,5 @@ func newReplicateTaskSlice() []*replicateTask {
 
 func releaseReplicateTaskSlice(rts []*replicateTask) {
 	rts = rts[0:0]
-	replicateTaskSlicePool.Put(rts)
+	replicateTaskSlicePool.Put(rts) //nolint:staticcheck
 }
diff --git a/internal/storagenode/logstream/sequencer.go b/internal/storagenode/logstream/sequencer.go
index 3e4acd7c4..149be111f 100644
--- a/internal/storagenode/logstream/sequencer.go
+++ b/internal/storagenode/logstream/sequencer.go
@@ -108,6 +108,7 @@ func (sq *sequencer) sequenceLoopInternal(ctx context.Context, st *sequenceTask)
 			// NOTE: Use "append" since the length of st.rts is not enough to use index. Its capacity is enough because it is created to be reused.
 			st.rts[replicaIdx].llsnList = append(st.rts[replicaIdx].llsnList, sq.llsn)
 		}
+		//nolint:staticcheck
 		if err := st.wb.Set(sq.llsn, st.dataBatch[dataIdx]); err != nil {
 			// TODO: handle error
 		}
diff --git a/internal/stress/stress.go b/internal/stress/stress.go
index 2d5b6ce64..990933b83 100644
--- a/internal/stress/stress.go
+++ b/internal/stress/stress.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 
 	"github.com/kakao/varlog/pkg/types"
 	"github.com/kakao/varlog/pkg/varlog"
@@ -124,7 +125,7 @@ func Append(config Config) error {
 		go func() {
 			defer wg.Done()
 			vlog, err := varlog.Open(ctx, config.ClusterID, config.MRAddrs, varlog.WithGRPCDialOptions(
-				grpc.WithInsecure(),
+				grpc.WithTransportCredentials(insecure.NewCredentials()),
 				grpc.WithReadBufferSize(1<<20),
 				grpc.WithWriteBufferSize(32<<20),
 			))
diff --git a/internal/varlogcli/append.go b/internal/varlogcli/append.go
index 82a82dfce..965de726b 100644
--- a/internal/varlogcli/append.go
+++ b/internal/varlogcli/append.go
@@ -82,7 +82,6 @@ func appendInternal(mrAddrs []string, clusterID types.ClusterID, batchSize int,
 				batch = batch[0:0]
 			case <-ctx.Done():
 				return ctx.Err()
-			default:
 			}
 		}
 		if len(batch) > 0 {
diff --git a/internal/varlogctl/controller_test.go b/internal/varlogctl/controller_test.go
index 548ca513c..e0a589faa 100644
--- a/internal/varlogctl/controller_test.go
+++ b/internal/varlogctl/controller_test.go
@@ -3,7 +3,6 @@ package varlogctl_test
 import (
 	"context"
 	"flag"
-	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -416,7 +415,7 @@ func TestController(t *testing.T) {
 				return
 			}
 
-			want, err := ioutil.ReadFile(path)
+			want, err := os.ReadFile(path)
 			assert.NoError(t, err)
 
 			if len(got) > 0 || len(want) > 0 {
diff --git a/pkg/rpc/rpc_conn.go b/pkg/rpc/rpc_conn.go
index cd70a2857..59608b02b 100644
--- a/pkg/rpc/rpc_conn.go
+++ b/pkg/rpc/rpc_conn.go
@@ -6,10 +6,11 @@ import (
 
 	"github.com/pkg/errors"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 )
 
 var (
-	defaultDialOption = []grpc.DialOption{grpc.WithInsecure()}
+	defaultDialOption = []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
 )
 
 type Conn struct {
diff --git a/pkg/util/fputil/dirsize_test.go b/pkg/util/fputil/dirsize_test.go
index 429d64a5a..3b9f390ee 100644
--- a/pkg/util/fputil/dirsize_test.go
+++ b/pkg/util/fputil/dirsize_test.go
@@ -2,7 +2,7 @@ package fputil
 
 import (
 	"io/fs"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"testing"
 
@@ -18,7 +18,7 @@ func TestDirectorySize(t *testing.T) {
 	path := t.TempDir()
 	assert.Zero(t, DirectorySize(path))
 
-	assert.NoError(t, ioutil.WriteFile(filepath.Join(path, "foo"), []byte{'a'}, fs.FileMode(777)))
+	assert.NoError(t, os.WriteFile(filepath.Join(path, "foo"), []byte{'a'}, fs.FileMode(0777)))
 	assert.EqualValues(t, 1, DirectorySize(path))
 }
 
diff --git a/pkg/util/fputil/filepath.go b/pkg/util/fputil/filepath.go
index c7c60ccd2..d054d90f4 100644
--- a/pkg/util/fputil/filepath.go
+++ b/pkg/util/fputil/filepath.go
@@ -1,7 +1,6 @@
 package fputil
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 
@@ -19,7 +18,7 @@ func IsWritableDir(dir string) error {
 		return errors.WithStack(err)
 	}
 	filename := filepath.Join(dir, touchFileName)
-	if err := ioutil.WriteFile(filename, []byte(""), touchFileMode); err != nil {
+	if err := os.WriteFile(filename, []byte(""), touchFileMode); err != nil {
 		return errors.WithStack(err)
 	}
 	err = os.Remove(filename)
diff --git a/pkg/util/testutil/conveyutil/conveyutil.go b/pkg/util/testutil/conveyutil/conveyutil.go
index a19be02ec..152518543 100644
--- a/pkg/util/testutil/conveyutil/conveyutil.go
+++ b/pkg/util/testutil/conveyutil/conveyutil.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/smartystreets/goconvey/convey"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 
 	"github.com/kakao/varlog/pkg/util/netutil"
 )
@@ -35,7 +36,11 @@ func WithServiceServer(s service, testf func(server *grpc.Server, addr string))
 		// addr := testutil.GetLocalAddress(lis)
 		ctx, cancel := context.WithCancel(context.Background())
 		defer cancel()
-		conn, err := grpc.DialContext(ctx, addr, grpc.WithInsecure(), grpc.WithBlock(), grpc.FailOnNonTempDialError(true))
+		conn, err := grpc.DialContext(ctx, addr,
+			grpc.WithTransportCredentials(insecure.NewCredentials()),
+			grpc.WithBlock(),
+			grpc.FailOnNonTempDialError(true),
+		)
 		convey.So(err, convey.ShouldBeNil)
 		convey.So(conn.Close(), convey.ShouldBeNil)
 
diff --git a/pkg/varlog/options.go b/pkg/varlog/options.go
index bda4957f1..2f090f1d0 100644
--- a/pkg/varlog/options.go
+++ b/pkg/varlog/options.go
@@ -5,6 +5,7 @@ import (
 
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 )
 
 const (
@@ -36,7 +37,7 @@ func defaultOptions() options {
 		expireDenyInterval: defaultExpireDenyInterval,
 		logger:             zap.NewNop(),
 		grpcDialOptions: []grpc.DialOption{
-			grpc.WithInsecure(),
+			grpc.WithTransportCredentials(insecure.NewCredentials()),
 			grpc.WithReadBufferSize(1 << 20),
 			grpc.WithWriteBufferSize(1 << 20),
 		},
diff --git a/pkg/varlogtest/log.go b/pkg/varlogtest/log.go
index 025eb06b5..cb8ed5f42 100644
--- a/pkg/varlogtest/log.go
+++ b/pkg/varlogtest/log.go
@@ -292,7 +292,7 @@ func (c *testLog) LogStreamMetadata(_ context.Context, topicID types.TopicID, lo
 
 	logStreamDesc = *proto.Clone(&logStreamDesc).(*varlogpb.LogStreamDescriptor)
 	head, tail := c.vt.peek(topicID, logStreamID)
-	logStreamDesc.Head = head
+	logStreamDesc.Head = head //nolint:staticcheck
 	logStreamDesc.Tail = tail
 	return logStreamDesc, nil
 }
diff --git a/pkg/varlogtest/varlogtest_test.go b/pkg/varlogtest/varlogtest_test.go
index 07bb89b24..5c29b9708 100644
--- a/pkg/varlogtest/varlogtest_test.go
+++ b/pkg/varlogtest/varlogtest_test.go
@@ -145,7 +145,7 @@ func TestVarlogTest(t *testing.T) {
 		require.Equal(t, varlogpb.LogEntryMeta{
 			TopicID:     topicID,
 			LogStreamID: logStreamID,
-		}, logStreamDesc.Head)
+		}, logStreamDesc.Head) //nolint:staticcheck
 		require.Equal(t, varlogpb.LogEntryMeta{
 			TopicID:     topicID,
 			LogStreamID: logStreamID,
@@ -326,8 +326,8 @@ func TestVarlogTest(t *testing.T) {
 		for _, lsID := range topicLogStreamsMap[tpID] {
 			lsDesc, err := vlg.LogStreamMetadata(context.Background(), tpID, lsID)
 			require.NoError(t, err)
-			require.GreaterOrEqual(t, lsDesc.Tail.LLSN, lsDesc.Head.LLSN)
-			subscribeTo(tpID, lsID, lsDesc.Head.LLSN, lsDesc.Tail.LLSN+1)
+			require.GreaterOrEqual(t, lsDesc.Tail.LLSN, lsDesc.Head.LLSN) //nolint:staticcheck
+			subscribeTo(tpID, lsID, lsDesc.Head.LLSN, lsDesc.Tail.LLSN+1) //nolint:staticcheck
 
 			lsd, err := adm.Unseal(context.Background(), tpID, lsID)
 			require.NoError(t, err)
@@ -345,8 +345,8 @@ func TestVarlogTest(t *testing.T) {
 		for _, lsID := range lsIDs {
 			lsDesc, err := vlg.LogStreamMetadata(context.Background(), tpID, lsID)
 			require.NoError(t, err)
-			require.GreaterOrEqual(t, lsDesc.Tail.LLSN, lsDesc.Head.LLSN)
-			subscribeTo(tpID, lsID, lsDesc.Head.LLSN, lsDesc.Tail.LLSN+1)
+			require.GreaterOrEqual(t, lsDesc.Tail.LLSN, lsDesc.Head.LLSN) //nolint:staticcheck
+			subscribeTo(tpID, lsID, lsDesc.Head.LLSN, lsDesc.Tail.LLSN+1) //nolint:staticcheck
 		}
 	}
 
@@ -356,7 +356,7 @@ func TestVarlogTest(t *testing.T) {
 
 	lsDesc, err := vlg.LogStreamMetadata(context.Background(), tpID, lsID)
 	require.NoError(t, err)
-	require.Equal(t, types.MinLLSN, lsDesc.Head.LLSN)
+	require.Equal(t, types.MinLLSN, lsDesc.Head.LLSN) //nolint:staticcheck
 	require.GreaterOrEqual(t, lsDesc.Tail.LLSN, types.LLSN(minLogsPerTopic))
 
 	ctx1, cancel1 := context.WithCancel(context.Background())
@@ -523,15 +523,15 @@ func TestVarlogTest_Trim(t *testing.T) {
 
 	lsd, err := vlg.LogStreamMetadata(context.Background(), td.TopicID, lsds[0].LogStreamID)
 	assert.NoError(t, err)
-	assert.Equal(t, types.LLSN(3), lsd.Head.LLSN)
-	assert.Equal(t, types.GLSN(5), lsd.Head.GLSN)
+	assert.Equal(t, types.LLSN(3), lsd.Head.LLSN) //nolint:staticcheck
+	assert.Equal(t, types.GLSN(5), lsd.Head.GLSN) //nolint:staticcheck
 	assert.Equal(t, types.LLSN(5), lsd.Tail.LLSN)
 	assert.Equal(t, types.GLSN(9), lsd.Tail.GLSN)
 
 	lsd, err = vlg.LogStreamMetadata(context.Background(), td.TopicID, lsds[1].LogStreamID)
 	assert.NoError(t, err)
-	assert.Equal(t, types.LLSN(2), lsd.Head.LLSN)
-	assert.Equal(t, types.GLSN(4), lsd.Head.GLSN)
+	assert.Equal(t, types.LLSN(2), lsd.Head.LLSN) //nolint:staticcheck
+	assert.Equal(t, types.GLSN(4), lsd.Head.GLSN) //nolint:staticcheck
 	assert.Equal(t, types.LLSN(5), lsd.Tail.LLSN)
 	assert.Equal(t, types.GLSN(10), lsd.Tail.GLSN)
 
diff --git a/tests/ee/k8s/vault/vault.go b/tests/ee/k8s/vault/vault.go
index 8c075523b..35d2e44df 100644
--- a/tests/ee/k8s/vault/vault.go
+++ b/tests/ee/k8s/vault/vault.go
@@ -3,7 +3,7 @@ package vault
 import (
 	"encoding/json"
 	"flag"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"os"
 	"testing"
@@ -51,7 +51,7 @@ func GetClusterConnectionInfo(t *testing.T) ClusterConnectionInfo {
 		assert.NoError(t, err)
 	}()
 
-	body, err := ioutil.ReadAll(rsp.Body)
+	body, err := io.ReadAll(rsp.Body)
 	require.NoError(t, err)
 
 	var response Response
diff --git a/tests/it/cluster/client_test.go b/tests/it/cluster/client_test.go
index e00588ad7..66956c841 100644
--- a/tests/it/cluster/client_test.go
+++ b/tests/it/cluster/client_test.go
@@ -208,10 +208,10 @@ func TestClientAppend(t *testing.T) {
 		require.Equal(t, topicID, lsd.TopicID)
 		require.Equal(t, logStreamID, lsd.LogStreamID)
 
-		require.Equal(t, types.MinLLSN, lsd.Head.LLSN)
-		require.GreaterOrEqual(t, lsd.Head.GLSN, types.MinGLSN)
-		require.Equal(t, topicID, lsd.Head.TopicID)
-		require.Equal(t, logStreamID, lsd.Head.LogStreamID)
+		require.Equal(t, types.MinLLSN, lsd.Head.LLSN)          //nolint:staticcheck
+		require.GreaterOrEqual(t, lsd.Head.GLSN, types.MinGLSN) //nolint:staticcheck
+		require.Equal(t, topicID, lsd.Head.TopicID)             //nolint:staticcheck
+		require.Equal(t, logStreamID, lsd.Head.LogStreamID)     //nolint:staticcheck
 
 		require.GreaterOrEqual(t, lsd.Tail.LLSN, types.MinLLSN)
 		require.GreaterOrEqual(t, lsd.Tail.GLSN, types.MinGLSN)
diff --git a/tests/it/management/management_test.go b/tests/it/management/management_test.go
index e91562b56..3f8a54824 100644
--- a/tests/it/management/management_test.go
+++ b/tests/it/management/management_test.go
@@ -526,7 +526,7 @@ func TestSealLogStreamSealedIncompletely(t *testing.T) {
 				So(err, ShouldBeNil)
 
 				So(testutil.CompareWaitN(100, func() bool {
-					meta, err := env.GetVMS().Metadata(context.TODO())
+					meta, err := env.GetVMS().Metadata(context.TODO()) //nolint:staticcheck
 					if err != nil {
 						return false
 					}
diff --git a/tests/it/testenv.go b/tests/it/testenv.go
index 80e3049aa..228902d7b 100644
--- a/tests/it/testenv.go
+++ b/tests/it/testenv.go
@@ -1563,7 +1563,7 @@ func (clus *VarlogCluster) WaitCommit(t *testing.T, lsID types.LogStreamID, vers
 func (clus *VarlogCluster) WaitSealed(t *testing.T, lsID types.LogStreamID) {
 	// FIXME: do not use vms.RELOAD_INTERVAL
 	require.Eventually(t, func() bool {
-		vmsMeta, err := clus.vmsServer.Metadata(context.Background())
+		vmsMeta, err := clus.vmsServer.Metadata(context.Background()) //nolint:staticcheck
 		return err == nil && vmsMeta.GetLogStream(lsID) != nil
 	}, mrmanager.ReloadInterval*10, 100*time.Millisecond)