diff --git a/cmd/format.go b/cmd/format.go
index 948a9189c4b3..182f7406968e 100644
--- a/cmd/format.go
+++ b/cmd/format.go
@@ -142,6 +142,10 @@ Details: https://juicefs.com/docs/community/quick_start_guide`,
 				Value: 1,
 				Usage: "number of days after which removed files will be permanently deleted",
 			},
+			&cli.BoolFlag{
+				Name:  "hash-prefix",
+				Usage: "give each object a hashed prefix",
+			},
 			&cli.BoolFlag{
 				Name:  "force",
 				Usage: "overwrite existing format",
@@ -320,6 +324,7 @@ func format(c *cli.Context) error {
 			SecretKey:   c.String("secret-key"),
 			EncryptKey:  loadEncrypt(c.String("encrypt-rsa-key")),
 			Shards:      c.Int("shards"),
+			HashPrefix:  c.Bool("hash-prefix"),
 			Capacity:    c.Uint64("capacity") << 30,
 			Inodes:      c.Uint64("inodes"),
 			BlockSize:   fixObjectSize(c.Int("block-size")),
@@ -361,6 +366,8 @@ func format(c *cli.Context) error {
 				format.Compression = c.String(flag)
 			case "shards":
 				format.Shards = c.Int(flag)
+			case "hash-prefix":
+				format.HashPrefix = c.Bool(flag)
 			case "storage":
 				format.Storage = c.String(flag)
 			case "encrypt-rsa-key":
diff --git a/cmd/mount.go b/cmd/mount.go
index eb5c6a3bcead..558c98fc5be0 100644
--- a/cmd/mount.go
+++ b/cmd/mount.go
@@ -278,8 +278,9 @@ func newStore(format *meta.Format, chunkConf *chunk.Config, registerer prometheu
 
 func getChunkConf(c *cli.Context, format *meta.Format) *chunk.Config {
 	chunkConf := &chunk.Config{
-		BlockSize: format.BlockSize * 1024,
-		Compress:  format.Compression,
+		BlockSize:  format.BlockSize * 1024,
+		Compress:   format.Compression,
+		HashPrefix: format.HashPrefix,
 
 		GetTimeout:    time.Second * time.Duration(c.Int("get-timeout")),
 		PutTimeout:    time.Second * time.Duration(c.Int("put-timeout")),
diff --git a/pkg/chunk/cached_store.go b/pkg/chunk/cached_store.go
index 07fce3b3ae59..b82cb4abe620 100644
--- a/pkg/chunk/cached_store.go
+++ b/pkg/chunk/cached_store.go
@@ -134,7 +134,7 @@ func (c *rChunk) blockSize(indx int) int {
 }
 
 func (c *rChunk) key(indx int) string {
-	if c.store.conf.Partitions > 1 {
+	if c.store.conf.HashPrefix {
 		return fmt.Sprintf("chunks/%02X/%v/%v_%v_%v", c.id%256, c.id/1000/1000, c.id, indx, c.blockSize(indx))
 	}
 	return fmt.Sprintf("chunks/%v/%v/%v_%v_%v", c.id/1000/1000, c.id/1000, c.id, indx, c.blockSize(indx))
@@ -623,7 +623,7 @@ type Config struct {
 	DownloadLimit  int64 // bytes per second
 	Writeback      bool
 	UploadDelay    time.Duration
-	Partitions     int
+	HashPrefix     bool
 	BlockSize      int
 	GetTimeout     time.Duration
 	PutTimeout     time.Duration
diff --git a/pkg/chunk/cached_store_test.go b/pkg/chunk/cached_store_test.go
index 01fc9685adbd..e46a60ef017d 100644
--- a/pkg/chunk/cached_store_test.go
+++ b/pkg/chunk/cached_store_test.go
@@ -205,7 +205,7 @@ func TestStoreDelayed(t *testing.T) {
 func TestStoreMultiBuckets(t *testing.T) {
 	mem, _ := object.CreateStorage("mem", "", "", "")
 	conf := defaultConf
-	conf.Partitions = 3
+	conf.HashPrefix = true
 	store := NewCachedStore(mem, conf, nil)
 	testStore(t, store)
 }
diff --git a/pkg/meta/config.go b/pkg/meta/config.go
index 9b185fdda0cf..2cd7deafad3b 100644
--- a/pkg/meta/config.go
+++ b/pkg/meta/config.go
@@ -52,7 +52,7 @@ type Format struct {
 	BlockSize        int
 	Compression      string
 	Shards           int
-	Partitions       int
+	HashPrefix       bool
 	Capacity         uint64
 	Inodes           uint64
 	EncryptKey       string `json:",omitempty"`
diff --git a/pkg/meta/metadata-sub.sample b/pkg/meta/metadata-sub.sample
index 676801defe8a..043f06bffa71 100644
--- a/pkg/meta/metadata-sub.sample
+++ b/pkg/meta/metadata-sub.sample
@@ -9,7 +9,7 @@
     "BlockSize": 4096,
     "Compression": "none",
     "Shards": 0,
-    "Partitions": 0,
+    "HashPrefix": false,
     "Capacity": 0,
     "Inodes": 0,
     "EncryptKey": "AQSttslKOSE/hQT/gmaMniCsdPF8JdPRfoYK6zFkdUOnifYwBA==",
diff --git a/pkg/meta/metadata.sample b/pkg/meta/metadata.sample
index d6136200c655..0149a8b0e7a9 100644
--- a/pkg/meta/metadata.sample
+++ b/pkg/meta/metadata.sample
@@ -9,7 +9,7 @@
     "BlockSize": 4096,
     "Compression": "none",
     "Shards": 0,
-    "Partitions": 0,
+    "HashPrefix": false,
     "Capacity": 0,
     "Inodes": 0,
     "EncryptKey": "AQSttslKOSE/hQT/gmaMniCsdPF8JdPRfoYK6zFkdUOnifYwBA==",
diff --git a/sdk/java/libjfs/main.go b/sdk/java/libjfs/main.go
index ee73f64c883c..72a6c238a116 100644
--- a/sdk/java/libjfs/main.go
+++ b/sdk/java/libjfs/main.go
@@ -464,7 +464,7 @@ func jfs_init(cname, jsonConf, user, group, superuser, supergroup *C.char) uintp
 			DownloadLimit:  int64(jConf.DownloadLimit) * 1e6 / 8,
 			Prefetch:       jConf.Prefetch,
 			Writeback:      jConf.Writeback,
-			Partitions:     format.Partitions,
+			HashPrefix:     format.HashPrefix,
 			GetTimeout:     time.Second * time.Duration(jConf.GetTimeout),
 			PutTimeout:     time.Second * time.Duration(jConf.PutTimeout),
 			BufferSize:     jConf.MemorySize << 20,