diff --git a/cmd/bench.go b/cmd/bench.go
index 96329ac55d1e..479034947ff0 100644
--- a/cmd/bench.go
+++ b/cmd/bench.go
@@ -298,15 +298,11 @@ func (bm *benchmark) printResult(result [][3]string) {
 }
 
 func bench(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-
+	setup(ctx, 1)
 	/* --- Pre-check --- */
 	if ctx.Uint("block-size") == 0 || ctx.Uint("threads") == 0 {
 		return os.ErrInvalid
 	}
-	if ctx.NArg() < 1 {
-		logger.Fatalln("PATH must be provided")
-	}
 	tmpdir, err := filepath.Abs(ctx.Args().First())
 	if err != nil {
 		logger.Fatalf("Failed to get absolute path of %s: %s", ctx.Args().First(), err)
diff --git a/cmd/config.go b/cmd/config.go
index 1f94739aaaf1..c16c84ab2909 100644
--- a/cmd/config.go
+++ b/cmd/config.go
@@ -108,10 +108,7 @@ func userConfirmed() bool {
 }
 
 func config(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		return fmt.Errorf("META-URL is needed")
-	}
+	setup(ctx, 1)
 	removePassword(ctx.Args().Get(0))
 	m := meta.NewClient(ctx.Args().Get(0), &meta.Config{Retries: 10, Strict: true})
 
diff --git a/cmd/destroy.go b/cmd/destroy.go
index 42efa0841bff..cf3ce4a63fbe 100644
--- a/cmd/destroy.go
+++ b/cmd/destroy.go
@@ -103,10 +103,7 @@ func printSessions(ss [][3]string) string {
 }
 
 func destroy(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 2 {
-		return fmt.Errorf("META-URL and UUID are required")
-	}
+	setup(ctx, 2)
 	uri := ctx.Args().Get(0)
 	if !strings.Contains(uri, "://") {
 		uri = "redis://" + uri
diff --git a/cmd/dump.go b/cmd/dump.go
index 02194f1ad74f..69ba6253b95a 100644
--- a/cmd/dump.go
+++ b/cmd/dump.go
@@ -17,7 +17,6 @@
 package main
 
 import (
-	"fmt"
 	"io"
 	"os"
 
@@ -54,10 +53,7 @@ Details: https://juicefs.com/docs/community/metadata_dump_load`,
 }
 
 func dump(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		return fmt.Errorf("META-URL is needed")
-	}
+	setup(ctx, 1)
 	var fp io.WriteCloser
 	if ctx.Args().Len() == 1 {
 		fp = os.Stdout
diff --git a/cmd/format.go b/cmd/format.go
index d08bdf837b04..a29b43ebe068 100644
--- a/cmd/format.go
+++ b/cmd/format.go
@@ -271,16 +271,9 @@ func test(store object.ObjectStorage) error {
 }
 
 func format(c *cli.Context) error {
-	setLoggerLevel(c)
-	if c.Args().Len() < 1 {
-		logger.Fatalf("Meta URL and name are required")
-	}
+	setup(c, 2)
 	removePassword(c.Args().Get(0))
 	m := meta.NewClient(c.Args().Get(0), &meta.Config{Retries: 2})
-
-	if c.Args().Len() < 2 {
-		logger.Fatalf("Please give it a name")
-	}
 	name := c.Args().Get(1)
 	validName := regexp.MustCompile(`^[a-z0-9][a-z0-9\-]{1,61}[a-z0-9]$`)
 	if !validName.MatchString(name) {
diff --git a/cmd/fsck.go b/cmd/fsck.go
index fbde8d4a8382..903018e3cc54 100644
--- a/cmd/fsck.go
+++ b/cmd/fsck.go
@@ -48,10 +48,7 @@ $ juicefs fsck redis://localhost`,
 }
 
 func fsck(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		return fmt.Errorf("META-URL is needed")
-	}
+	setup(ctx, 1)
 	removePassword(ctx.Args().Get(0))
 	m := meta.NewClient(ctx.Args().Get(0), &meta.Config{Retries: 10, Strict: true})
 	format, err := m.Load(true)
diff --git a/cmd/gateway.go b/cmd/gateway.go
index a40f2bb85805..1e0e7d00dd06 100644
--- a/cmd/gateway.go
+++ b/cmd/gateway.go
@@ -85,12 +85,7 @@ Details: https://juicefs.com/docs/community/s3_gateway`,
 }
 
 func gateway(c *cli.Context) error {
-	setLoggerLevel(c)
-
-	if c.Args().Len() < 2 {
-		logger.Fatalf("Meta URL and listen address are required")
-	}
-
+	setup(c, 2)
 	ak := os.Getenv("MINIO_ROOT_USER")
 	if ak == "" {
 		ak = os.Getenv("MINIO_ACCESS_KEY")
diff --git a/cmd/gc.go b/cmd/gc.go
index b5c9ec549a1f..228be256f386 100644
--- a/cmd/gc.go
+++ b/cmd/gc.go
@@ -17,7 +17,6 @@
 package main
 
 import (
-	"fmt"
 	"os"
 	"strconv"
 	"strings"
@@ -80,10 +79,7 @@ type dChunk struct {
 }
 
 func gc(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		return fmt.Errorf("META-URL is needed")
-	}
+	setup(ctx, 1)
 	removePassword(ctx.Args().Get(0))
 	m := meta.NewClient(ctx.Args().Get(0), &meta.Config{
 		Retries:    10,
diff --git a/cmd/info.go b/cmd/info.go
index 13a33a62d5f9..d92cadc98aa9 100644
--- a/cmd/info.go
+++ b/cmd/info.go
@@ -62,14 +62,11 @@ $ juicefs info -i 100`,
 }
 
 func info(ctx *cli.Context) error {
+	setup(ctx, 1)
 	if runtime.GOOS == "windows" {
 		logger.Infof("Windows is not supported")
 		return nil
 	}
-	if ctx.Args().Len() < 1 {
-		logger.Infof("DIR or FILE is needed")
-		return nil
-	}
 	var recursive uint8
 	if ctx.Bool("recursive") {
 		recursive = 1
diff --git a/cmd/load.go b/cmd/load.go
index 3038e47fcb32..a989fe09fdaa 100644
--- a/cmd/load.go
+++ b/cmd/load.go
@@ -17,7 +17,6 @@
 package main
 
 import (
-	"fmt"
 	"io"
 	"os"
 
@@ -45,10 +44,7 @@ Details: https://juicefs.com/docs/community/metadata_dump_load`,
 }
 
 func load(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		return fmt.Errorf("META-URL is needed")
-	}
+	setup(ctx, 1)
 	var fp io.ReadCloser
 	if ctx.Args().Len() == 1 {
 		fp = os.Stdin
diff --git a/cmd/main.go b/cmd/main.go
index fda35ac5c9a2..87c1cfc4743f 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -236,22 +236,14 @@ func reorderOptions(app *cli.App, args []string) []string {
 	return append(newArgs, others...)
 }
 
-func setupAgent(c *cli.Context) {
-	if !c.Bool("no-agent") {
-		go func() {
-			for port := 6060; port < 6100; port++ {
-				_ = http.ListenAndServe(fmt.Sprintf("127.0.0.1:%d", port), nil)
-			}
-		}()
-		go func() {
-			for port := 6070; port < 6100; port++ {
-				_ = agent.Listen(agent.Options{Addr: fmt.Sprintf("127.0.0.1:%d", port)})
-			}
-		}()
+// Check number of positional arguments, set logger level and setup agent if needed
+func setup(c *cli.Context, n int) {
+	if c.NArg() < n {
+		logger.Errorf("This command requires at lease %d arguments", n)
+		fmt.Printf("USAGE:\n   juicefs %s [command options] %s\n", c.Command.Name, c.Command.ArgsUsage)
+		os.Exit(1)
 	}
-}
 
-func setLoggerLevel(c *cli.Context) {
 	if c.Bool("trace") {
 		utils.SetLogLevel(logrus.TraceLevel)
 	} else if c.Bool("verbose") {
@@ -264,7 +256,19 @@ func setLoggerLevel(c *cli.Context) {
 	if c.Bool("no-color") {
 		utils.DisableLogColor()
 	}
-	setupAgent(c)
+
+	if !c.Bool("no-agent") {
+		go func() {
+			for port := 6060; port < 6100; port++ {
+				_ = http.ListenAndServe(fmt.Sprintf("127.0.0.1:%d", port), nil)
+			}
+		}()
+		go func() {
+			for port := 6070; port < 6100; port++ {
+				_ = agent.Listen(agent.Options{Addr: fmt.Sprintf("127.0.0.1:%d", port)})
+			}
+		}()
+	}
 }
 
 func removePassword(uri string) {
diff --git a/cmd/mount.go b/cmd/mount.go
index 0850644cacc4..1e51f5596271 100644
--- a/cmd/mount.go
+++ b/cmd/mount.go
@@ -317,14 +317,8 @@ func initBackgroundTasks(c *cli.Context, vfsConf *vfs.Config, metaConf *meta.Con
 }
 
 func mount(c *cli.Context) error {
-	setLoggerLevel(c)
-	if c.Args().Len() < 1 {
-		logger.Fatalf("Meta URL and mountpoint are required")
-	}
+	setup(c, 2)
 	addr := c.Args().Get(0)
-	if c.Args().Len() < 2 {
-		logger.Fatalf("MOUNTPOINT is required")
-	}
 	mp := c.Args().Get(1)
 
 	prepareMp(mp)
diff --git a/cmd/profile.go b/cmd/profile.go
index bc76bafd9d92..51f5c4a2e542 100644
--- a/cmd/profile.go
+++ b/cmd/profile.go
@@ -331,10 +331,7 @@ func (p *profiler) flusher() {
 }
 
 func profile(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		logger.Fatalln("Mount point or log file must be provided!")
-	}
+	setup(ctx, 1)
 	logPath := ctx.Args().First()
 	st, err := os.Stat(logPath)
 	if err != nil {
diff --git a/cmd/rmr.go b/cmd/rmr.go
index ad48f243655b..04952cdb8095 100644
--- a/cmd/rmr.go
+++ b/cmd/rmr.go
@@ -57,14 +57,11 @@ func openController(path string) *os.File {
 }
 
 func rmr(ctx *cli.Context) error {
+	setup(ctx, 1)
 	if runtime.GOOS == "windows" {
 		logger.Infof("Windows is not supported")
 		return nil
 	}
-	if ctx.Args().Len() < 1 {
-		logger.Infof("PATH is needed")
-		return nil
-	}
 	for i := 0; i < ctx.Args().Len(); i++ {
 		path := ctx.Args().Get(i)
 		p, err := filepath.Abs(path)
diff --git a/cmd/stats.go b/cmd/stats.go
index 200961ecb0d6..7631bf440499 100644
--- a/cmd/stats.go
+++ b/cmd/stats.go
@@ -366,10 +366,7 @@ func readStats(path string) map[string]float64 {
 }
 
 func stats(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		logger.Fatalln("mount point must be provided")
-	}
+	setup(ctx, 1)
 	mp := ctx.Args().First()
 	inode, err := utils.GetFileInode(mp)
 	if err != nil {
diff --git a/cmd/status.go b/cmd/status.go
index 249baef80095..b87e06410f3c 100644
--- a/cmd/status.go
+++ b/cmd/status.go
@@ -62,10 +62,7 @@ func printJson(v interface{}) {
 }
 
 func status(ctx *cli.Context) error {
-	setLoggerLevel(ctx)
-	if ctx.Args().Len() < 1 {
-		return fmt.Errorf("META-URL is needed")
-	}
+	setup(ctx, 1)
 	removePassword(ctx.Args().Get(0))
 	m := meta.NewClient(ctx.Args().Get(0), &meta.Config{Retries: 10, Strict: true})
 	format, err := m.Load(true)
diff --git a/cmd/sync.go b/cmd/sync.go
index 1dca9069f67f..17df631618be 100644
--- a/cmd/sync.go
+++ b/cmd/sync.go
@@ -44,6 +44,7 @@ func cmdSync() *cli.Command {
 		ArgsUsage: "SRC DST",
 		Description: `
 This tool spawns multiple threads to concurrently syncs objects of two data storages.
+SRC and DST should be [NAME://][ACCESS_KEY:SECRET_KEY@]BUCKET[.ENDPOINT][/PREFIX].
 
 Examples:
 # Sync object from OSS to S3
@@ -278,16 +279,8 @@ func isS3PathType(endpoint string) bool {
 	return regexp.MustCompile(pattern).MatchString(endpoint)
 }
 
-const USAGE = `juicefs [options] sync [options] SRC DST
-SRC and DST should be [NAME://][ACCESS_KEY:SECRET_KEY@]BUCKET[.ENDPOINT][/PREFIX]`
-
 func doSync(c *cli.Context) error {
-	setLoggerLevel(c)
-
-	if c.Args().Len() != 2 {
-		logger.Errorf(USAGE)
-		return nil
-	}
+	setup(c, 2)
 	config := sync.NewConfigFromCli(c)
 	go func() { _ = http.ListenAndServe(fmt.Sprintf("127.0.0.1:%d", config.HTTPPort), nil) }()
 
diff --git a/cmd/umount.go b/cmd/umount.go
index e3ae9c3b89c5..9893b30ae0ea 100644
--- a/cmd/umount.go
+++ b/cmd/umount.go
@@ -88,9 +88,7 @@ func doUmount(mp string, force bool) error {
 }
 
 func umount(ctx *cli.Context) error {
-	if ctx.Args().Len() < 1 {
-		return fmt.Errorf("MOUNTPOINT is needed")
-	}
+	setup(ctx, 1)
 	mp := ctx.Args().Get(0)
 	force := ctx.Bool("force")
 	return doUmount(mp, force)
diff --git a/cmd/warmup.go b/cmd/warmup.go
index 0689af2b52f7..8d345f4c0619 100644
--- a/cmd/warmup.go
+++ b/cmd/warmup.go
@@ -102,6 +102,7 @@ func sendCommand(cf *os.File, batch []string, count int, threads uint, backgroun
 }
 
 func warmup(ctx *cli.Context) error {
+	setup(ctx, 0)
 	fname := ctx.String("file")
 	paths := ctx.Args().Slice()
 	if fname != "" {
diff --git a/cmd/webdav.go b/cmd/webdav.go
index 4e85d0194aa0..f03f88e7bea0 100644
--- a/cmd/webdav.go
+++ b/cmd/webdav.go
@@ -61,14 +61,8 @@ $ juicefs webdav redis://localhost localhost:9007`,
 }
 
 func webdav(c *cli.Context) error {
-	setLoggerLevel(c)
-	if c.Args().Len() < 1 {
-		logger.Fatalf("meta url are required")
-	}
+	setup(c, 2)
 	metaUrl := c.Args().Get(0)
-	if c.Args().Len() < 2 {
-		logger.Fatalf("listen address is required")
-	}
 	listenAddr := c.Args().Get(1)
 	m, store, conf := initForSvc(c, "webdav", metaUrl)
 	jfs, err := fs.NewFileSystem(conf, m, store)