diff --git a/blobstore/common/errors/errors.go b/blobstore/common/errors/errors.go
index f9e5c4596..4a9cde65a 100644
--- a/blobstore/common/errors/errors.go
+++ b/blobstore/common/errors/errors.go
@@ -162,6 +162,7 @@ var errCodeMap = map[int]string{
 	CodeShardNoLeader:               "shardnode:shard has no leader",
 	CodeIllegalSlices:               "shardnode:alloc with illegal slices",
 	CodeBlobAlreadyExists:           "shardnode:blob already exists",
+	CodeShardConflicts:              "shardnode:shard conflicts",
 }
 
 // HTTPError make rpc.HTTPError
diff --git a/blobstore/common/errors/shardnode.go b/blobstore/common/errors/shardnode.go
index 7f3f995d4..bc888ccfd 100644
--- a/blobstore/common/errors/shardnode.go
+++ b/blobstore/common/errors/shardnode.go
@@ -25,6 +25,7 @@ const (
 	CodeIllegalSlices               = 1008
 	CodeBlobAlreadyExists           = 1009
 	CodeUnsupport                   = 1010
+	CodeShardConflicts              = 1011
 )
 
 // 10xx
@@ -39,4 +40,5 @@ var (
 	ErrIllegalSlices               = newError(CodeIllegalSlices, "illegal slices")
 	ErrBlobAlreadyExists           = newError(CodeBlobAlreadyExists, "blob already exists")
 	ErrShardNodeUnsupport          = newError(CodeUnsupport, "unsupport shard node")
+	ErrShardConflicts              = newError(CodeShardConflicts, "shard conflicts")
 )
diff --git a/blobstore/shardnode/storage/disk.go b/blobstore/shardnode/storage/disk.go
index a1785d37d..f12547d4f 100644
--- a/blobstore/shardnode/storage/disk.go
+++ b/blobstore/shardnode/storage/disk.go
@@ -132,6 +132,7 @@ func OpenDisk(ctx context.Context, cfg DiskConfig) (*Disk, error) {
 	disk.diskInfo = diskInfo
 	disk.store = store
 	disk.shardsMu.shards = make(map[proto.Suid]*shard)
+	disk.shardsMu.shardCheck = make(map[proto.ShardID]struct{})
 
 	// disk will be gc by finalizer
 	runtime.SetFinalizer(disk, func(disk *Disk) {
@@ -181,7 +182,8 @@ type Disk struct {
 	shardsMu struct {
 		sync.RWMutex
 		// shard id as the map key
-		shards map[proto.Suid]*shard
+		shards     map[proto.Suid]*shard
+		shardCheck map[proto.ShardID]struct{}
 	}
 	raftManager raft.Manager
 	store       *store.Store
@@ -243,6 +245,7 @@ func (d *Disk) Load(ctx context.Context) error {
 
 		d.shardsMu.Lock()
 		d.shardsMu.shards[suid] = shard
+		d.shardsMu.shardCheck[suid.ShardID()] = struct{}{}
 		d.shardsMu.Unlock()
 
 		shard.Start()
@@ -269,6 +272,11 @@ func (d *Disk) AddShard(ctx context.Context, suid proto.Suid,
 		return nil
 	}
 
+	if _, ok := d.shardsMu.shardCheck[suid.ShardID()]; ok {
+		span.Errorf("shard[%d] already exist", suid.ShardID())
+		return apierr.ErrShardConflicts
+	}
+
 	shardUnits := make([]clustermgr.ShardUnit, len(nodes))
 	for i := range nodes {
 		shardUnits[i] = clustermgr.ShardUnit{
@@ -305,6 +313,7 @@ func (d *Disk) AddShard(ctx context.Context, suid proto.Suid,
 	}
 
 	d.shardsMu.shards[suid] = shard
+	d.shardsMu.shardCheck[suid.ShardID()] = struct{}{}
 	shard.Start()
 	return nil
 }
@@ -375,6 +384,7 @@ func (d *Disk) DeleteShard(ctx context.Context, suid proto.Suid, version proto.R
 	}
 
 	delete(d.shardsMu.shards, suid)
+	delete(d.shardsMu.shardCheck, suid.ShardID())
 
 	return nil
 }
@@ -484,6 +494,7 @@ func (d *Disk) SetBroken() bool {
 func (d *Disk) ResetShards() {
 	d.lock.Lock()
 	d.shardsMu.shards = make(map[proto.Suid]*shard)
+	d.shardsMu.shardCheck = make(map[proto.ShardID]struct{})
 	d.lock.Unlock()
 }
 
diff --git a/blobstore/shardnode/storage/proto.go b/blobstore/shardnode/storage/proto.go
index d0ece1bb2..5e459b888 100644
--- a/blobstore/shardnode/storage/proto.go
+++ b/blobstore/shardnode/storage/proto.go
@@ -52,7 +52,7 @@ type (
 // todo: merge these encode and decode function into shard?
 
 func shardDataPrefixSize() int {
-	return len(shardDataPrefix) + 8
+	return len(shardDataPrefix) + 4
 }
 
 func shardInfoPrefixSize() int {
@@ -91,19 +91,19 @@ func decodeShardInfoPrefix(raw []byte) proto.Suid {
 	return proto.Suid(binary.BigEndian.Uint64(raw[prefixSize:]))
 }
 
-func encodeShardDataPrefix(suid proto.Suid, raw []byte) {
+func encodeShardDataPrefix(shardID proto.ShardID, raw []byte) {
 	copy(raw, shardDataPrefix)
-	binary.BigEndian.PutUint64(raw[len(shardDataPrefix):], uint64(suid))
+	binary.BigEndian.PutUint32(raw[len(shardDataPrefix):], uint32(shardID))
 }
 
-func encodeShardItemPrefix(suid proto.Suid, raw []byte) {
+func encodeShardItemPrefix(shardID proto.ShardID, raw []byte) {
 	shardPrefixSize := shardDataPrefixSize()
-	encodeShardDataPrefix(suid, raw)
+	encodeShardDataPrefix(shardID, raw)
 	copy(raw[shardPrefixSize:], itemSuffix)
 }
 
-func encodeShardDataMaxPrefix(suid proto.Suid, raw []byte) {
+func encodeShardDataMaxPrefix(shardID proto.ShardID, raw []byte) {
 	shardPrefixSize := shardDataPrefixSize()
-	encodeShardDataPrefix(suid, raw)
+	encodeShardDataPrefix(shardID, raw)
 	copy(raw[shardPrefixSize:], maxSuffix)
 }
diff --git a/blobstore/shardnode/storage/shard.go b/blobstore/shardnode/storage/shard.go
index c6d1af456..a33616259 100644
--- a/blobstore/shardnode/storage/shard.go
+++ b/blobstore/shardnode/storage/shard.go
@@ -880,7 +880,7 @@ type shardKeysGenerator struct {
 func (s *shardKeysGenerator) encodeItemKey(key []byte) []byte {
 	shardItemPrefixSize := shardItemPrefixSize()
 	newKey := make([]byte, shardItemPrefixSize+len(key))
-	encodeShardItemPrefix(s.suid, newKey)
+	encodeShardItemPrefix(s.suid.ShardID(), newKey)
 	copy(newKey[shardItemPrefixSize:], key)
 	return newKey
 }
@@ -904,7 +904,7 @@ func (s *shardKeysGenerator) encodeShardInfoKey() []byte {
 // it can be used for listing all shard's data or delete shard's data
 func (s *shardKeysGenerator) encodeShardDataPrefix() []byte {
 	key := make([]byte, shardDataPrefixSize())
-	encodeShardDataPrefix(s.suid, key)
+	encodeShardDataPrefix(s.suid.ShardID(), key)
 	return key
 }
 
@@ -912,7 +912,7 @@ func (s *shardKeysGenerator) encodeShardDataPrefix() []byte {
 // it can be used for delete shard's data
 func (s *shardKeysGenerator) encodeShardDataMaxPrefix() []byte {
 	key := make([]byte, shardMaxPrefixSize())
-	encodeShardDataMaxPrefix(s.suid, key)
+	encodeShardDataMaxPrefix(s.suid.ShardID(), key)
 	return key
 }
 
diff --git a/blobstore/shardnode/storage/shard_sm.go b/blobstore/shardnode/storage/shard_sm.go
index 6ff6ce009..5861414fe 100644
--- a/blobstore/shardnode/storage/shard_sm.go
+++ b/blobstore/shardnode/storage/shard_sm.go
@@ -196,6 +196,8 @@ func (s *shardSM) ApplySnapshot(header raft.RaftSnapshotHeader, snap raft.Snapsh
 	// clear all data with shard prefix
 	batch := kvStore.NewWriteBatch()
 	batch.DeleteRange(dataCF, s.shardKeys.encodeShardDataPrefix(), s.shardKeys.encodeShardDataMaxPrefix())
+	// flush
+
 	if err := kvStore.Write(ctx, batch, nil); err != nil {
 		return err
 	}