diff --git a/logger/logger_test.go b/logger/logger_test.go
index f22f8211..9111c0a2 100644
--- a/logger/logger_test.go
+++ b/logger/logger_test.go
@@ -17,7 +17,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -177,7 +176,7 @@ func TestLogger(t *testing.T) {
 	checkLogger("Unable to close logger: dummy error")
 
 	// Switch to file log
-	tmpDir, err := ioutil.TempDir("", "")
+	tmpDir, err := os.MkdirTemp("", "")
 	if err != nil {
 		t.Fatalf("Unable to create temp dir: %v", err)
 	}
@@ -188,7 +187,7 @@ func TestLogger(t *testing.T) {
 	logger.SetFileSizeLimit(1000)
 	// Reopen and check file content
 	logger.ReopenLogFile()
-	buf, err := ioutil.ReadFile(fname)
+	buf, err := os.ReadFile(fname)
 	if err != nil {
 		t.Fatalf("Error reading file: %v", err)
 	}
@@ -201,7 +200,7 @@ func TestLogger(t *testing.T) {
 	for i := 0; i < 100; i++ {
 		logger.Noticef(notice)
 	}
-	files, err := ioutil.ReadDir(tmpDir)
+	files, err := os.ReadDir(tmpDir)
 	if err != nil {
 		t.Fatalf("Unable to read temp dir: %v", err)
 	}
diff --git a/server/clustering_test.go b/server/clustering_test.go
index 9b6f7b13..528db6c4 100644
--- a/server/clustering_test.go
+++ b/server/clustering_test.go
@@ -18,7 +18,6 @@ import (
 	"database/sql"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"math/rand"
 	"net"
 	"net/http"
@@ -46,7 +45,7 @@ import (
 var defaultRaftLog string
 
 func init() {
-	tmpDir, err := ioutil.TempDir("", "raft_logs_")
+	tmpDir, err := os.MkdirTemp("", "raft_logs_")
 	if err != nil {
 		panic("Could not create tmp dir")
 	}
@@ -3679,7 +3678,7 @@ func TestClusteringRaftLogReplayDoesNotDeleteLatestVersionOfChannel(t *testing.T
 	follower := removeServer(servers, leader)[0]
 	follower.Shutdown()
 	witnessFile := filepath.Join(follower.opts.FilestoreDir, channel, "deleted.txt")
-	if err := ioutil.WriteFile(witnessFile, []byte("if present, channel has not been deleted then recreated"), 0666); err != nil {
+	if err := os.WriteFile(witnessFile, []byte("if present, channel has not been deleted then recreated"), 0666); err != nil {
 		t.Fatalf("Error creating file: %v", err)
 	}
 	// Now restart..
@@ -4551,7 +4550,7 @@ func TestClusteringWithCryptoStore(t *testing.T) {
 
 	check := func(t *testing.T, name, fname string) {
 		t.Helper()
-		content, err := ioutil.ReadFile(fname)
+		content, err := os.ReadFile(fname)
 		if err != nil {
 			t.Fatalf("Error reading file %q: %v", fname1, err)
 		}
@@ -6770,7 +6769,7 @@ func TestClusteringRestoreSnapshotMsgsBailIfNoLeader(t *testing.T) {
 		return nil
 	})
 
-	snaps, err := ioutil.ReadDir(filepath.Join(defaultRaftLog, "c", clusterName, "snapshots"))
+	snaps, err := os.ReadDir(filepath.Join(defaultRaftLog, "c", clusterName, "snapshots"))
 	if err != nil {
 		t.Fatalf("Error reading snapshots directory: %v", err)
 	}
diff --git a/server/conf_test.go b/server/conf_test.go
index e54e1631..395d6486 100644
--- a/server/conf_test.go
+++ b/server/conf_test.go
@@ -16,7 +16,6 @@ package server
 import (
 	"bytes"
 	"flag"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"runtime"
@@ -314,11 +313,11 @@ func TestParsePermError(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.SkipNow()
 	}
-	tmpDir, err := ioutil.TempDir("", "streaming")
+	tmpDir, err := os.MkdirTemp("", "streaming")
 	if err != nil {
 		t.Fatalf("Could not create tmp dir: %v", err)
 	}
-	file, err := ioutil.TempFile(tmpDir, "config.conf")
+	file, err := os.CreateTemp(tmpDir, "config.conf")
 	if err != nil {
 		t.Fatalf("Could not create tmp file: %v", err)
 	}
@@ -339,7 +338,7 @@ func TestParsePermError(t *testing.T) {
 
 func TestParseParserError(t *testing.T) {
 	confFile := "wrong_config.conf"
-	if err := ioutil.WriteFile(confFile, []byte("x=."), 0660); err != nil {
+	if err := os.WriteFile(confFile, []byte("x=."), 0660); err != nil {
 		t.Fatalf("Unexpected error creating conf file: %v", err)
 	}
 	defer os.Remove(confFile)
@@ -351,7 +350,7 @@ func TestParseParserError(t *testing.T) {
 
 func TestParseStoreType(t *testing.T) {
 	confFile := "wrong_config.conf"
-	if err := ioutil.WriteFile(confFile, []byte("store=memory"), 0660); err != nil {
+	if err := os.WriteFile(confFile, []byte("store=memory"), 0660); err != nil {
 		t.Fatalf("Unexpected error creating conf file: %v", err)
 	}
 	defer os.Remove(confFile)
@@ -364,7 +363,7 @@ func TestParseStoreType(t *testing.T) {
 	}
 	os.Remove(confFile)
 
-	if err := ioutil.WriteFile(confFile, []byte("store=xyz"), 0660); err != nil {
+	if err := os.WriteFile(confFile, []byte("store=xyz"), 0660); err != nil {
 		t.Fatalf("Unexpected error creating conf file: %v", err)
 	}
 	defer os.Remove(confFile)
@@ -380,7 +379,7 @@ func TestParseStoreType(t *testing.T) {
 		stores.TypeSQL,
 	}
 	for _, gs := range goodStores {
-		if err := ioutil.WriteFile(confFile, []byte("store="+gs), 0660); err != nil {
+		if err := os.WriteFile(confFile, []byte("store="+gs), 0660); err != nil {
 			t.Fatalf("Unexpected error creating conf file: %v", err)
 		}
 		defer os.Remove(confFile)
@@ -398,7 +397,7 @@ func TestParseStoreType(t *testing.T) {
 func TestParsePerChannelLimitsSetToZero(t *testing.T) {
 	confFile := "config.conf"
 	defer os.Remove(confFile)
-	if err := ioutil.WriteFile(confFile,
+	if err := os.WriteFile(confFile,
 		[]byte("store_limits: {channels: {foo: {max_msgs: 0, max_bytes: 0, max_age: \"0\", max_subs: 0, max_inactivity: \"0\"}}}"), 0660); err != nil {
 		t.Fatalf("Unexpected error creating conf file: %v", err)
 	}
@@ -532,7 +531,7 @@ func TestParseWrongTypes(t *testing.T) {
 
 func expectFailureFor(t *testing.T, content, errorMatch string) {
 	confFile := "wrong_config.conf"
-	if err := ioutil.WriteFile(confFile, []byte(content), 0660); err != nil {
+	if err := os.WriteFile(confFile, []byte(content), 0660); err != nil {
 		t.Fatalf("Unexpected error creating conf file: %v", err)
 	}
 	defer os.Remove(confFile)
@@ -637,7 +636,7 @@ func TestParseConfigureOptions(t *testing.T) {
 		streaming: {
 			cluster_id: my_cluster
 		}`)
-	if err := ioutil.WriteFile(sconf, scontent, 0660); err != nil {
+	if err := os.WriteFile(sconf, scontent, 0660); err != nil {
 		t.Fatalf("Error creating conf file: %v", err)
 	}
 	ncontent := []byte(`
@@ -645,7 +644,7 @@ func TestParseConfigureOptions(t *testing.T) {
 		streaming: {
 			cluster_id: my_cluster_2
 		}`)
-	if err := ioutil.WriteFile(nconf, ncontent, 0660); err != nil {
+	if err := os.WriteFile(nconf, ncontent, 0660); err != nil {
 		t.Fatalf("Error creating conf file: %v", err)
 	}
 	sopts, nopts := mustNotFail([]string{"-sc", sconf, "-c", nconf})
@@ -700,7 +699,7 @@ func TestParseConfigureOptions(t *testing.T) {
 		} else {
 			ncontent = []byte(`logtime: true`)
 		}
-		if err := ioutil.WriteFile(nconf, ncontent, 0660); err != nil {
+		if err := os.WriteFile(nconf, ncontent, 0660); err != nil {
 			t.Fatalf("Error creating conf file: %v", err)
 		}
 		_, nopts = mustNotFail([]string{"-c", nconf})
diff --git a/server/monitor_test.go b/server/monitor_test.go
index be9fda5f..4af7f459 100644
--- a/server/monitor_test.go
+++ b/server/monitor_test.go
@@ -18,9 +18,10 @@ import (
 	"crypto/x509"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"math/rand"
 	"net/http"
+	"os"
 	"reflect"
 	"runtime"
 	"strings"
@@ -81,7 +82,7 @@ func getBodyEx(t *testing.T, client *http.Client, scheme, endpoint string, mp, e
 	if ct != expectedContentType {
 		stackFatalf(t, "Expected %s content-type, got %s\n", expectedContentType, ct)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		resp.Body.Close()
 		stackFatalf(t, "Got an error reading the body: %v\n", err)
@@ -155,7 +156,7 @@ func TestMonitorStartOwnHTTPSServer(t *testing.T) {
 	defer s.Shutdown()
 
 	tlsConfig := &tls.Config{}
-	caCert, err := ioutil.ReadFile("../test/certs/ca.pem")
+	caCert, err := os.ReadFile("../test/certs/ca.pem")
 	if err != nil {
 		t.Fatalf("Got error reading RootCA file: %s", err)
 	}
@@ -1494,7 +1495,7 @@ func TestMonitorNoPanicOnServerRestart(t *testing.T) {
 				if err != nil {
 					continue
 				}
-				ioutil.ReadAll(resp.Body)
+				io.ReadAll(resp.Body)
 				resp.Body.Close()
 				select {
 				case <-done:
diff --git a/server/server_run_test.go b/server/server_run_test.go
index 4c942076..0b73527d 100644
--- a/server/server_run_test.go
+++ b/server/server_run_test.go
@@ -17,7 +17,6 @@ import (
 	"crypto/tls"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"runtime"
@@ -1283,12 +1282,12 @@ func TestStreamingServerReadyLog(t *testing.T) {
 }
 
 func TestReopenLogFileStopsNATSDebugTrace(t *testing.T) {
-	tmpDir, err := ioutil.TempDir("", "nats-streaming-server")
+	tmpDir, err := os.MkdirTemp("", "nats-streaming-server")
 	if err != nil {
 		t.Fatal("Could not create tmp dir")
 	}
 	defer os.RemoveAll(tmpDir)
-	file, err := ioutil.TempFile(tmpDir, "log_")
+	file, err := os.CreateTemp(tmpDir, "log_")
 	if err != nil {
 		t.Fatalf("Could not create the temp file: %v", err)
 	}
@@ -1311,7 +1310,7 @@ func TestReopenLogFileStopsNATSDebugTrace(t *testing.T) {
 
 	check := func(str string, expected bool) {
 		t.Helper()
-		buf, err := ioutil.ReadFile(nOpts.LogFile)
+		buf, err := os.ReadFile(nOpts.LogFile)
 		if err != nil {
 			t.Fatalf("Error reading file: %v", err)
 		}
@@ -1352,7 +1351,7 @@ func TestReopenLogFileStopsNATSDebugTrace(t *testing.T) {
 		s.log.Noticef(pstr)
 	}
 	// Check that size limit has been applied.
-	files, err := ioutil.ReadDir(tmpDir)
+	files, err := os.ReadDir(tmpDir)
 	if err != nil {
 		t.Fatalf("Error reading directory: %v", err)
 	}
diff --git a/server/server_test.go b/server/server_test.go
index 299f4a04..734547de 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -17,7 +17,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"regexp"
@@ -162,7 +161,7 @@ func TestMain(m *testing.M) {
 }
 
 func init() {
-	tmpDir, err := ioutil.TempDir(".", "data_server_")
+	tmpDir, err := os.MkdirTemp(".", "data_server_")
 	if err != nil {
 		panic("Could not create tmp dir")
 	}
@@ -409,13 +408,13 @@ func createConnectionWithNatsOpts(t tLogger, clientName string,
 
 func createConfFile(t *testing.T, content []byte) string {
 	t.Helper()
-	conf, err := ioutil.TempFile("", "")
+	conf, err := os.CreateTemp("", "")
 	if err != nil {
 		t.Fatalf("Error creating conf file: %v", err)
 	}
 	fName := conf.Name()
 	conf.Close()
-	if err := ioutil.WriteFile(fName, content, 0666); err != nil {
+	if err := os.WriteFile(fName, content, 0666); err != nil {
 		os.Remove(fName)
 		t.Fatalf("Error writing conf file: %v", err)
 	}
@@ -424,7 +423,7 @@ func createConfFile(t *testing.T, content []byte) string {
 
 func changeCurrentConfigContentWithNewContent(t *testing.T, curConfig string, content []byte) {
 	t.Helper()
-	if err := ioutil.WriteFile(curConfig, content, 0666); err != nil {
+	if err := os.WriteFile(curConfig, content, 0666); err != nil {
 		t.Fatalf("Error writing config: %v", err)
 	}
 }
diff --git a/server/signal_test.go b/server/signal_test.go
index af7e9f93..026dc206 100644
--- a/server/signal_test.go
+++ b/server/signal_test.go
@@ -19,7 +19,6 @@ package server
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"strings"
@@ -77,7 +76,7 @@ func TestSignalToReOpenLogFile(t *testing.T) {
 			// Add a trace
 			expectedStr := "This is a Notice"
 			s.log.Noticef(expectedStr)
-			buf, err := ioutil.ReadFile(logFile)
+			buf, err := os.ReadFile(logFile)
 			if err != nil {
 				t.Fatalf("Error reading file: %v", err)
 			}
@@ -92,7 +91,7 @@ func TestSignalToReOpenLogFile(t *testing.T) {
 			syscall.Kill(syscall.Getpid(), syscall.SIGUSR1)
 			// Wait a bit for action to be performed
 			waitFor(t, 2*time.Second, 15*time.Millisecond, func() error {
-				buf, err = ioutil.ReadFile(logFile)
+				buf, err = os.ReadFile(logFile)
 				if err != nil {
 					return fmt.Errorf("Error reading file: %v", err)
 				}
@@ -105,7 +104,7 @@ func TestSignalToReOpenLogFile(t *testing.T) {
 			// Make sure that new traces are added
 			expectedStr = "This is a new notice"
 			s.log.Noticef(expectedStr)
-			buf, err = ioutil.ReadFile(logFile)
+			buf, err = os.ReadFile(logFile)
 			if err != nil {
 				t.Fatalf("Error reading file: %v", err)
 			}
@@ -208,7 +207,7 @@ func TestNATSServerConfigReloadFollowedByReopen(t *testing.T) {
 	cmd.Start()
 	// Wait for it to print some startup trace
 	waitFor(t, 2*time.Second, 50*time.Millisecond, func() error {
-		content, err := ioutil.ReadFile(lfile)
+		content, err := os.ReadFile(lfile)
 		if err != nil {
 			return err
 		}
@@ -230,7 +229,7 @@ func TestNATSServerConfigReloadFollowedByReopen(t *testing.T) {
 	c.Close()
 	syscall.Kill(cmd.Process.Pid, syscall.SIGINT)
 	cmd.Wait()
-	content, err := ioutil.ReadFile(lfile)
+	content, err := os.ReadFile(lfile)
 	if err != nil {
 		t.Fatalf("Error reading log file: %v", err)
 	}
diff --git a/stores/cryptostore_test.go b/stores/cryptostore_test.go
index 08f18576..9ef9bdd1 100644
--- a/stores/cryptostore_test.go
+++ b/stores/cryptostore_test.go
@@ -16,7 +16,6 @@ package stores
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"strings"
@@ -240,7 +239,7 @@ func TestCryptoStoreUseEnvKey(t *testing.T) {
 
 	cs.Close()
 
-	datContent, err := ioutil.ReadFile(datFile)
+	datContent, err := os.ReadFile(datFile)
 	if err != nil {
 		t.Fatalf("Error reading file: %v", err)
 	}
@@ -399,7 +398,7 @@ func TestCryptoStoreCheckEncryptedStore(t *testing.T) {
 
 			s.Close()
 
-			datContent, err := ioutil.ReadFile(datFile)
+			datContent, err := os.ReadFile(datFile)
 			if err != nil {
 				t.Fatalf("Error reading file: %v", err)
 			}
@@ -411,7 +410,7 @@ func TestCryptoStoreCheckEncryptedStore(t *testing.T) {
 			}
 			// Only message store is encrypted, so subscription file
 			// should be in plain text.
-			subContent, err := ioutil.ReadFile(subFile)
+			subContent, err := os.ReadFile(subFile)
 			if err != nil {
 				t.Fatalf("Error reading file: %v", err)
 			}
diff --git a/stores/filestore.go b/stores/filestore.go
index 8c0f87e4..6c018618 100644
--- a/stores/filestore.go
+++ b/stores/filestore.go
@@ -19,7 +19,6 @@ import (
 	"fmt"
 	"hash/crc32"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -740,8 +739,10 @@ func checkFileVersion(r io.Reader) error {
 
 // writeRecord writes a record to `w`.
 // The record layout is as follows:
-// 8 bytes: 4 bytes for type and/or size combined
-//          4 bytes for CRC-32
+// 8 bytes:
+// - 4 bytes for type and/or size combined
+// - 4 bytes for CRC-32
+//
 // variable bytes: payload.
 // If a buffer is provided, this function uses it and expands it if necessary.
 // The function returns the buffer (possibly changed due to expansion) and the
@@ -793,7 +794,7 @@ func writeRecord(w io.Writer, buf []byte, recType recordType, rec record, recSiz
 }
 
 // readRecord reads a record from `r`, possibly checking the CRC-32 checksum.
-// When `buf`` is not nil, this function ensures the buffer is big enough to
+// When `buf` is not nil, this function ensures the buffer is big enough to
 // hold the payload (expanding if necessary). Therefore, this call always
 // return `buf`, regardless if there is an error or not.
 // The caller is indicating if the record is supposed to be typed or not.
@@ -1443,7 +1444,7 @@ func (fs *FileStore) Recover() (*RecoveredState, error) {
 }
 
 func (fs *FileStore) getChannelsDir() ([]os.FileInfo, error) {
-	files, err := ioutil.ReadDir(fs.fm.rootDir)
+	files, err := os.ReadDir(fs.fm.rootDir)
 	if err != nil {
 		return nil, err
 	}
@@ -1452,7 +1453,11 @@ func (fs *FileStore) getChannelsDir() ([]os.FileInfo, error) {
 		if !f.IsDir() {
 			continue
 		}
-		channels = append(channels, f)
+		finfo, err := f.Info()
+		if err != nil {
+			return nil, err
+		}
+		channels = append(channels, finfo)
 	}
 	return channels, nil
 }
@@ -1872,7 +1877,7 @@ func (fs *FileStore) compactClientFile(orgFileName string) error {
 
 // Return a temporary file (including file version)
 func getTempFile(rootDir, prefix string) (*os.File, error) {
-	tmpFile, err := ioutil.TempFile(rootDir, prefix)
+	tmpFile, err := os.CreateTemp(rootDir, prefix)
 	if err != nil {
 		return nil, err
 	}
@@ -2048,16 +2053,21 @@ func (fs *FileStore) newFileMsgStore(channelDirName, channel string, limits *Msg
 
 	// Recovery case
 	if doRecover {
-		var dirFiles []os.FileInfo
+		var dirEntries []os.DirEntry
 		var fseq int64
 		var datFile, idxFile *file
 		var useIdxFile bool
 
-		dirFiles, err = ioutil.ReadDir(channelDirName)
-		for _, file := range dirFiles {
-			if file.IsDir() {
+		dirEntries, err = os.ReadDir(channelDirName)
+		for _, entry := range dirEntries {
+			if entry.IsDir() {
 				continue
 			}
+			file, ierr := entry.Info()
+			if ierr != nil {
+				err = ierr
+				break
+			}
 			fileName := file.Name()
 			if !strings.HasPrefix(fileName, msgFilesPrefix) || !strings.HasSuffix(fileName, datSuffix) {
 				continue
diff --git a/stores/filestore_msg_test.go b/stores/filestore_msg_test.go
index 592cf68c..82afc103 100644
--- a/stores/filestore_msg_test.go
+++ b/stores/filestore_msg_test.go
@@ -16,7 +16,6 @@ package stores
 import (
 	"fmt"
 	"hash/crc32"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -83,11 +82,11 @@ func TestFSBadMsgFile(t *testing.T) {
 	// Corrupt data file. Index's last message will not match
 	// data file, so idx file will be removed and recovery from
 	// data file will be done, which should report failure.
-	datContent, err := ioutil.ReadFile(firstSliceFileName)
+	datContent, err := os.ReadFile(firstSliceFileName)
 	if err != nil {
 		t.Fatalf("Error reading %v: %v", firstSliceFileName, err)
 	}
-	if err := ioutil.WriteFile(firstSliceFileName, datContent[:len(datContent)-5], 0666); err != nil {
+	if err := os.WriteFile(firstSliceFileName, datContent[:len(datContent)-5], 0666); err != nil {
 		t.Fatalf("Error writing file %v: %v", firstSliceFileName, err)
 	}
 	// So we should fail to create the filestore
@@ -778,7 +777,7 @@ func TestFSArchiveScript(t *testing.T) {
 	cleanupFSDatastore(t)
 	defer cleanupFSDatastore(t)
 
-	tmpDir, err := ioutil.TempDir(".", "")
+	tmpDir, err := os.MkdirTemp(".", "")
 	if err != nil {
 		t.Fatalf("Unable to create temp dir: %v", err)
 	}
@@ -797,7 +796,7 @@ func TestFSArchiveScript(t *testing.T) {
 		scriptFile = fmt.Sprintf("%s/script_%v.sh", pwd, time.Now().UnixNano())
 		content = fmt.Sprintf("#!/bin/bash\nmkdir -p %s/%s/$1\nmv $2 $3 %s/%s/$1\n", pwd, tmpDir, pwd, tmpDir)
 	}
-	if err := ioutil.WriteFile(scriptFile, []byte(content), 0777); err != nil {
+	if err := os.WriteFile(scriptFile, []byte(content), 0777); err != nil {
 		t.Fatalf("Error creating script: %v", err)
 	}
 	defer os.Remove(scriptFile)
@@ -857,7 +856,7 @@ func TestFSArchiveScript(t *testing.T) {
 	// Create a script that will error out
 	os.Remove(scriptFile)
 	content = "xxx"
-	if err := ioutil.WriteFile(scriptFile, []byte(content), 0777); err != nil {
+	if err := os.WriteFile(scriptFile, []byte(content), 0777); err != nil {
 		t.Fatalf("Error creating script: %v", err)
 	}
 	defer os.Remove(scriptFile)
@@ -1347,7 +1346,7 @@ func TestFSPanicOnMsgExpireWithClosedDatFile(t *testing.T) {
 	ms.Lock()
 	idxFileName := ms.files[1].idxFile.name
 	os.Remove(idxFileName)
-	err := ioutil.WriteFile(idxFileName, []byte("xxxxxxx"), 0666)
+	err := os.WriteFile(idxFileName, []byte("xxxxxxx"), 0666)
 	ms.Unlock()
 	if err != nil {
 		t.Fatalf("Error rewriting index file: %v", err)
@@ -1698,11 +1697,11 @@ func TestFSExpirationWithTruncatedNonLastSlice(t *testing.T) {
 
 	s.Close()
 
-	datContent, err := ioutil.ReadFile(fname)
+	datContent, err := os.ReadFile(fname)
 	if err != nil {
 		t.Fatalf("Error reading %v: %v", fname, err)
 	}
-	if err := ioutil.WriteFile(fname, datContent[:len(datContent)-5], 0666); err != nil {
+	if err := os.WriteFile(fname, datContent[:len(datContent)-5], 0666); err != nil {
 		t.Fatalf("Error writing file %v: %v", fname, err)
 	}
 
@@ -1929,12 +1928,12 @@ func TestFSNoPanicOnRemoveMsg(t *testing.T) {
 	ms.Lock()
 	idxFile := ms.files[1].idxFile
 	ms.fm.closeLockedOrOpenedFile(idxFile)
-	content, err := ioutil.ReadFile(idxFile.name)
+	content, err := os.ReadFile(idxFile.name)
 	if err != nil {
 		t.Fatalf("Error reading file: %v", err)
 	}
 	copy(content[4:], []byte("xxx"))
-	if err := ioutil.WriteFile(idxFile.name, content, 0600); err != nil {
+	if err := os.WriteFile(idxFile.name, content, 0600); err != nil {
 		t.Fatalf("Error writing file: %v", err)
 	}
 	ms.Unlock()
@@ -2331,12 +2330,12 @@ func TestFSExpirationError(t *testing.T) {
 	ms.Lock()
 	idxFile := ms.files[1].idxFile
 	ms.fm.closeLockedOrOpenedFile(idxFile)
-	content, err := ioutil.ReadFile(idxFile.name)
+	content, err := os.ReadFile(idxFile.name)
 	if err != nil {
 		t.Fatalf("Error reading file: %v", err)
 	}
 	copy(content[4:], []byte("xxx"))
-	if err := ioutil.WriteFile(idxFile.name, content, 0600); err != nil {
+	if err := os.WriteFile(idxFile.name, content, 0600); err != nil {
 		t.Fatalf("Error writing file: %v", err)
 	}
 	ms.Unlock()
@@ -2385,7 +2384,7 @@ func TestFSMsgsFileVersionError(t *testing.T) {
 			s.Close()
 
 			os.Remove(fname)
-			if err := ioutil.WriteFile(fname, []byte(""), 0666); err != nil {
+			if err := os.WriteFile(fname, []byte(""), 0666); err != nil {
 				t.Fatalf("Error writing file: %v", err)
 			}
 
diff --git a/stores/filestore_sub_test.go b/stores/filestore_sub_test.go
index 44fe5154..08babba6 100644
--- a/stores/filestore_sub_test.go
+++ b/stores/filestore_sub_test.go
@@ -15,7 +15,6 @@ package stores
 
 import (
 	"hash/crc32"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -911,7 +910,7 @@ func TestFSSubscriptionsFileVersionError(t *testing.T) {
 	s.Close()
 
 	os.Remove(fname)
-	if err := ioutil.WriteFile(fname, []byte(""), 0666); err != nil {
+	if err := os.WriteFile(fname, []byte(""), 0666); err != nil {
 		t.Fatalf("Error writing file: %v", err)
 	}
 
diff --git a/stores/filestore_test.go b/stores/filestore_test.go
index 3a4ba01a..7fc2f2c8 100644
--- a/stores/filestore_test.go
+++ b/stores/filestore_test.go
@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"hash/crc32"
 	"io"
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"path"
@@ -46,7 +45,7 @@ var (
 var testFDsLimit = int64(5)
 
 func init() {
-	tmpDir, err := ioutil.TempDir(".", "data_stores_")
+	tmpDir, err := os.MkdirTemp(".", "data_stores_")
 	if err != nil {
 		panic("Could not create tmp dir")
 	}
@@ -1774,8 +1773,8 @@ func TestFSParallelRecovery(t *testing.T) {
 	numRoutines := runtime.NumGoroutine()
 	// Make several channels fail to recover
 	fname := fmt.Sprintf("%s.1.%s", msgFilesPrefix, datSuffix)
-	ioutil.WriteFile(filepath.Join(testFSDefaultDatastore, "foo.50", fname), []byte("dummy"), 0666)
-	ioutil.WriteFile(filepath.Join(testFSDefaultDatastore, "foo.51", fname), []byte("dummy"), 0666)
+	os.WriteFile(filepath.Join(testFSDefaultDatastore, "foo.50", fname), []byte("dummy"), 0666)
+	os.WriteFile(filepath.Join(testFSDefaultDatastore, "foo.51", fname), []byte("dummy"), 0666)
 	s, err := NewFileStore(testLogger, testFSDefaultDatastore, &testDefaultStoreLimits, ParallelRecovery(10))
 	if err == nil {
 		_, err = s.Recover()
@@ -2089,7 +2088,7 @@ func TestFSServerAndClientFilesVersionError(t *testing.T) {
 
 			s.Close()
 			os.Remove(fname)
-			if err := ioutil.WriteFile(fname, []byte(""), 0666); err != nil {
+			if err := os.WriteFile(fname, []byte(""), 0666); err != nil {
 				t.Fatalf("Error creating file: %v", err)
 			}
 
diff --git a/stores/raftstore_test.go b/stores/raftstore_test.go
index 5d1be27e..2a1c6cfb 100644
--- a/stores/raftstore_test.go
+++ b/stores/raftstore_test.go
@@ -15,7 +15,6 @@ package stores
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"testing"
@@ -27,7 +26,7 @@ import (
 var testRSDefaultDatastore string
 
 func init() {
-	tmpDir, err := ioutil.TempDir(".", "raft_data_stores_")
+	tmpDir, err := os.MkdirTemp(".", "raft_data_stores_")
 	if err != nil {
 		panic("Could not create tmp dir")
 	}
diff --git a/stores/store.go b/stores/store.go
index 1c8ee231..4d02b46a 100644
--- a/stores/store.go
+++ b/stores/store.go
@@ -143,7 +143,6 @@ type Channel struct {
 // If an implementation has a Store constructor with StoreLimits, it should be
 // noted that the limits don't apply to any state being recovered, for Store
 // implementations supporting recovery.
-//
 type Store interface {
 	// GetExclusiveLock is an advisory lock to prevent concurrent
 	// access to the store from multiple instances.