diff --git a/kernel/conf/stat.go b/kernel/conf/stat.go
index 55778ab5c..29825026c 100644
--- a/kernel/conf/stat.go
+++ b/kernel/conf/stat.go
@@ -23,6 +23,8 @@ type Stat struct {
 	CBlockCount int   `json:"cBlockCount"`
 	DataSize    int64 `json:"dataSize"`
 	CDataSize   int64 `json:"cDataSize"`
+	AssetsSize  int64 `json:"assetsSize"`
+	CAssetsSize int64 `json:"cAssetsSize"`
 }
 
 func NewStat() *Stat {
diff --git a/kernel/model/box.go b/kernel/model/box.go
index 173d2e2bb..f37a44878 100644
--- a/kernel/model/box.go
+++ b/kernel/model/box.go
@@ -26,11 +26,13 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/88250/gulu"
 	"github.com/88250/lute/ast"
 	"github.com/88250/lute/parse"
+	"github.com/dustin/go-humanize"
 	"github.com/facette/natsort"
 	"github.com/siyuan-note/filelock"
 	"github.com/siyuan-note/logging"
@@ -52,20 +54,29 @@ type Box struct {
 }
 
 func AutoStat() {
+	time.Sleep(time.Minute)
 	autoStat()
-	for range time.Tick(10 * time.Minute) {
+	for range time.Tick(2 * time.Hour) {
 		autoStat()
 	}
 }
 
+var statLock = sync.Mutex{}
+
 func autoStat() {
+	statLock.Lock()
+	defer statLock.Unlock()
+
 	Conf.Stat.TreeCount = treenode.CountTrees()
 	Conf.Stat.CTreeCount = treenode.CeilCount(Conf.Stat.TreeCount)
 	Conf.Stat.BlockCount = treenode.CountBlocks()
 	Conf.Stat.CBlockCount = treenode.CeilCount(Conf.Stat.BlockCount)
-	Conf.Stat.DataSize, _ = util.SizeOfDirectory(util.DataDir)
+	Conf.Stat.DataSize, Conf.Stat.AssetsSize = util.DataSize()
 	Conf.Stat.CDataSize = util.CeilSize(Conf.Stat.DataSize)
+	Conf.Stat.CAssetsSize = util.CeilSize(Conf.Stat.AssetsSize)
 	Conf.Save()
+
+	logging.LogInfof("auto stat [trees=%d, blocks=%d, dataSize=%s, assetsSize=%s]", Conf.Stat.TreeCount, Conf.Stat.BlockCount, humanize.Bytes(uint64(Conf.Stat.DataSize)), humanize.Bytes(uint64(Conf.Stat.AssetsSize)))
 }
 
 func ListNotebooks() (ret []*Box, err error) {
diff --git a/kernel/util/file.go b/kernel/util/file.go
index c1d788692..f40c1eab4 100644
--- a/kernel/util/file.go
+++ b/kernel/util/file.go
@@ -17,6 +17,7 @@
 package util
 
 import (
+	"io"
 	"os"
 	"path"
 	"path/filepath"
@@ -194,6 +195,27 @@ func SizeOfDirectory(path string) (size int64, err error) {
 	return
 }
 
+func DataSize() (dataSize, assetsSize int64) {
+	filepath.Walk(DataDir, func(path string, info os.FileInfo, err error) error {
+		if nil != err {
+			logging.LogErrorf("size of data failed: %s", err)
+			return io.EOF
+		}
+		if !info.IsDir() {
+			s := info.Size()
+			dataSize += s
+
+			if strings.Contains(strings.TrimPrefix(path, DataDir), "assets") {
+				assetsSize += s
+			}
+		} else {
+			dataSize += 4096
+		}
+		return nil
+	})
+	return
+}
+
 func CeilSize(size int64) int64 {
 	if 100*1024*1024 > size {
 		return 100 * 1024 * 1024
diff --git a/kernel/util/runtime.go b/kernel/util/runtime.go
index e9de5cdc9..412bc0ff6 100644
--- a/kernel/util/runtime.go
+++ b/kernel/util/runtime.go
@@ -25,7 +25,6 @@ import (
 
 	"github.com/88250/gulu"
 	"github.com/denisbrodbeck/machineid"
-	"github.com/dustin/go-humanize"
 	"github.com/siyuan-note/logging"
 )
 
@@ -41,9 +40,6 @@ const (
 )
 
 func logBootInfo() {
-	s, _ := SizeOfDirectory(DataDir)
-	dataDirSize := humanize.Bytes(uint64(s))
-
 	logging.LogInfof("kernel is booting:\n"+
 		"    * ver [%s]\n"+
 		"    * arch [%s]\n"+
@@ -53,8 +49,8 @@ func logBootInfo() {
 		"    * read only [%v]\n"+
 		"    * container [%s]\n"+
 		"    * database [ver=%s]\n"+
-		"    * workspace directory [%s, data %s]",
-		Ver, runtime.GOARCH, os.Getpid(), Mode, WorkingDir, ReadOnly, Container, DatabaseVer, WorkspaceDir, dataDirSize)
+		"    * workspace directory [%s]",
+		Ver, runtime.GOARCH, os.Getpid(), Mode, WorkingDir, ReadOnly, Container, DatabaseVer, WorkspaceDir)
 }
 
 func IsMutexLocked(m *sync.Mutex) bool {