diff --git a/weed/filer2/filechunks.go b/weed/filer2/filechunks.go
index 39e43cf3c..1cdd4d852 100644
--- a/weed/filer2/filechunks.go
+++ b/weed/filer2/filechunks.go
@@ -33,7 +33,7 @@ func ETag(chunks []*filer_pb.FileChunk) (etag string) {
 
 func CompactFileChunks(chunks []*filer_pb.FileChunk) (compacted, garbage []*filer_pb.FileChunk) {
 
-	visibles := nonOverlappingVisibleIntervals(chunks)
+	visibles := NonOverlappingVisibleIntervals(chunks)
 
 	fileIds := make(map[string]bool)
 	for _, interval := range visibles {
@@ -75,7 +75,13 @@ type ChunkView struct {
 
 func ViewFromChunks(chunks []*filer_pb.FileChunk, offset int64, size int) (views []*ChunkView) {
 
-	visibles := nonOverlappingVisibleIntervals(chunks)
+	visibles := NonOverlappingVisibleIntervals(chunks)
+
+	return ViewFromVisibleIntervals(visibles, offset, size)
+
+}
+
+func ViewFromVisibleIntervals(visibles []*VisibleInterval, offset int64, size int) (views []*ChunkView) {
 
 	stop := offset + int64(size)
 
@@ -97,7 +103,7 @@ func ViewFromChunks(chunks []*filer_pb.FileChunk, offset int64, size int) (views
 
 }
 
-func logPrintf(name string, visibles []*visibleInterval) {
+func logPrintf(name string, visibles []*VisibleInterval) {
 	/*
 		log.Printf("%s len %d", name, len(visibles))
 		for _, v := range visibles {
@@ -108,11 +114,11 @@ func logPrintf(name string, visibles []*visibleInterval) {
 
 var bufPool = sync.Pool{
 	New: func() interface{} {
-		return new(visibleInterval)
+		return new(VisibleInterval)
 	},
 }
 
-func mergeIntoVisibles(visibles, newVisibles []*visibleInterval, chunk *filer_pb.FileChunk) []*visibleInterval {
+func mergeIntoVisibles(visibles, newVisibles []*VisibleInterval, chunk *filer_pb.FileChunk) []*VisibleInterval {
 
 	newV := newVisibleInterval(
 		chunk.Offset,
@@ -173,13 +179,13 @@ func mergeIntoVisibles(visibles, newVisibles []*visibleInterval, chunk *filer_pb
 	return newVisibles
 }
 
-func nonOverlappingVisibleIntervals(chunks []*filer_pb.FileChunk) (visibles []*visibleInterval) {
+func NonOverlappingVisibleIntervals(chunks []*filer_pb.FileChunk) (visibles []*VisibleInterval) {
 
 	sort.Slice(chunks, func(i, j int) bool {
 		return chunks[i].Mtime < chunks[j].Mtime
 	})
 
-	var newVislbles []*visibleInterval
+	var newVislbles []*VisibleInterval
 	for _, chunk := range chunks {
 		newVislbles = mergeIntoVisibles(visibles, newVislbles, chunk)
 		t := visibles[:0]
@@ -196,7 +202,7 @@ func nonOverlappingVisibleIntervals(chunks []*filer_pb.FileChunk) (visibles []*v
 // find non-overlapping visible intervals
 // visible interval map to one file chunk
 
-type visibleInterval struct {
+type VisibleInterval struct {
 	start        int64
 	stop         int64
 	modifiedTime int64
@@ -204,8 +210,8 @@ type visibleInterval struct {
 	isFullChunk  bool
 }
 
-func newVisibleInterval(start, stop int64, fileId string, modifiedTime int64, isFullChunk bool) *visibleInterval {
-	return &visibleInterval{
+func newVisibleInterval(start, stop int64, fileId string, modifiedTime int64, isFullChunk bool) *VisibleInterval {
+	return &VisibleInterval{
 		start:        start,
 		stop:         stop,
 		fileId:       fileId,
diff --git a/weed/filer2/filechunks_test.go b/weed/filer2/filechunks_test.go
index c2dd18515..e75e60753 100644
--- a/weed/filer2/filechunks_test.go
+++ b/weed/filer2/filechunks_test.go
@@ -63,7 +63,7 @@ func TestIntervalMerging(t *testing.T) {
 
 	testcases := []struct {
 		Chunks   []*filer_pb.FileChunk
-		Expected []*visibleInterval
+		Expected []*VisibleInterval
 	}{
 		// case 0: normal
 		{
@@ -72,7 +72,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 100, Size: 100, FileId: "asdf", Mtime: 134},
 				{Offset: 200, Size: 100, FileId: "fsad", Mtime: 353},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 100, fileId: "abc"},
 				{start: 100, stop: 200, fileId: "asdf"},
 				{start: 200, stop: 300, fileId: "fsad"},
@@ -84,7 +84,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 0, Size: 100, FileId: "abc", Mtime: 123},
 				{Offset: 0, Size: 200, FileId: "asdf", Mtime: 134},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 200, fileId: "asdf"},
 			},
 		},
@@ -94,7 +94,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 0, Size: 100, FileId: "abc", Mtime: 123},
 				{Offset: 0, Size: 50, FileId: "asdf", Mtime: 134},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 50, fileId: "asdf"},
 				{start: 50, stop: 100, fileId: "abc"},
 			},
@@ -106,7 +106,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 0, Size: 200, FileId: "asdf", Mtime: 134},
 				{Offset: 50, Size: 250, FileId: "xxxx", Mtime: 154},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 50, fileId: "asdf"},
 				{start: 50, stop: 300, fileId: "xxxx"},
 			},
@@ -118,7 +118,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 0, Size: 200, FileId: "asdf", Mtime: 134},
 				{Offset: 250, Size: 250, FileId: "xxxx", Mtime: 154},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 200, fileId: "asdf"},
 				{start: 250, stop: 500, fileId: "xxxx"},
 			},
@@ -131,7 +131,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 70, Size: 150, FileId: "abc", Mtime: 143},
 				{Offset: 80, Size: 100, FileId: "xxxx", Mtime: 134},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 200, fileId: "asdf"},
 				{start: 200, stop: 220, fileId: "abc"},
 			},
@@ -143,7 +143,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 0, Size: 100, FileId: "abc", Mtime: 123},
 				{Offset: 0, Size: 100, FileId: "abc", Mtime: 123},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 100, fileId: "abc"},
 			},
 		},
@@ -157,7 +157,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 8388608, Size: 3145728, FileId: "5,02982f80de50", Mtime: 160},
 				{Offset: 11534336, Size: 2842193, FileId: "7,0299ad723803", Mtime: 170},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 2097152, fileId: "3,029565bf3092"},
 				{start: 2097152, stop: 5242880, fileId: "6,029632f47ae2"},
 				{start: 5242880, stop: 8388608, fileId: "2,029734c5aa10"},
@@ -174,7 +174,7 @@ func TestIntervalMerging(t *testing.T) {
 				{Offset: 208896, Size: 339968 - 208896, FileId: "2,0b4031a72689", Mtime: 150},
 				{Offset: 339968, Size: 471040 - 339968, FileId: "3,0b416a557362", Mtime: 160},
 			},
-			Expected: []*visibleInterval{
+			Expected: []*VisibleInterval{
 				{start: 0, stop: 77824, fileId: "4,0b3df938e301"},
 				{start: 77824, stop: 208896, fileId: "4,0b3f0c7202f0"},
 				{start: 208896, stop: 339968, fileId: "2,0b4031a72689"},
@@ -186,7 +186,7 @@ func TestIntervalMerging(t *testing.T) {
 
 	for i, testcase := range testcases {
 		log.Printf("++++++++++ merged test case %d ++++++++++++++++++++", i)
-		intervals := nonOverlappingVisibleIntervals(testcase.Chunks)
+		intervals := NonOverlappingVisibleIntervals(testcase.Chunks)
 		for x, interval := range intervals {
 			log.Printf("test case %d, interval %d, start=%d, stop=%d, fileId=%s",
 				i, x, interval.start, interval.stop, interval.fileId)
diff --git a/weed/filesys/dir.go b/weed/filesys/dir.go
index 810916967..267bd44a1 100644
--- a/weed/filesys/dir.go
+++ b/weed/filesys/dir.go
@@ -7,11 +7,11 @@ import (
 	"path/filepath"
 	"time"
 
-	"github.com/seaweedfs/fuse"
-	"github.com/seaweedfs/fuse/fs"
 	"github.com/chrislusf/seaweedfs/weed/filer2"
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/fuse"
+	"github.com/seaweedfs/fuse/fs"
 )
 
 type Dir struct {
@@ -101,10 +101,11 @@ func (dir *Dir) Attr(context context.Context, attr *fuse.Attr) error {
 
 func (dir *Dir) newFile(name string, entry *filer_pb.Entry) *File {
 	return &File{
-		Name:  name,
-		dir:   dir,
-		wfs:   dir.wfs,
-		entry: entry,
+		Name:           name,
+		dir:            dir,
+		wfs:            dir.wfs,
+		entry:          entry,
+		entryViewCache: nil,
 	}
 }
 
diff --git a/weed/filesys/file.go b/weed/filesys/file.go
index d0f94a21b..a9e763a1b 100644
--- a/weed/filesys/file.go
+++ b/weed/filesys/file.go
@@ -1,12 +1,12 @@
 package filesys
 
 import (
-	"github.com/seaweedfs/fuse"
-	"github.com/seaweedfs/fuse/fs"
 	"context"
 	"github.com/chrislusf/seaweedfs/weed/filer2"
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/fuse"
+	"github.com/seaweedfs/fuse/fs"
 	"os"
 	"path/filepath"
 	"time"
@@ -20,11 +20,12 @@ var _ = fs.NodeFsyncer(&File{})
 var _ = fs.NodeSetattrer(&File{})
 
 type File struct {
-	Name   string
-	dir    *Dir
-	wfs    *WFS
-	entry  *filer_pb.Entry
-	isOpen bool
+	Name           string
+	dir            *Dir
+	wfs            *WFS
+	entry          *filer_pb.Entry
+	entryViewCache []*filer2.VisibleInterval
+	isOpen         bool
 }
 
 func (file *File) fullpath() string {
@@ -82,6 +83,7 @@ func (file *File) Setattr(ctx context.Context, req *fuse.SetattrRequest, resp *f
 		if req.Size == 0 {
 			// fmt.Printf("truncate %v \n", fullPath)
 			file.entry.Chunks = nil
+			file.entryViewCache = nil
 		}
 		file.entry.Attributes.FileSize = req.Size
 	}
@@ -138,6 +140,7 @@ func (file *File) maybeLoadAttributes(ctx context.Context) error {
 		if item != nil && !item.Expired() {
 			entry := item.Value().(*filer_pb.Entry)
 			file.entry = entry
+			file.entryViewCache = nil
 			// glog.V(1).Infof("file attr read cached %v attributes", file.Name)
 		} else {
 			err := file.wfs.withFilerClient(func(client filer_pb.SeaweedFilerClient) error {
@@ -154,6 +157,7 @@ func (file *File) maybeLoadAttributes(ctx context.Context) error {
 				}
 
 				file.entry = resp.Entry
+				file.entryViewCache = nil
 
 				glog.V(3).Infof("file attr %v %+v: %d", file.fullpath(), file.entry.Attributes, filer2.TotalSize(file.entry.Chunks))
 
diff --git a/weed/filesys/filehandle.go b/weed/filesys/filehandle.go
index a11fb06c6..8e1d6fadd 100644
--- a/weed/filesys/filehandle.go
+++ b/weed/filesys/filehandle.go
@@ -1,14 +1,14 @@
 package filesys
 
 import (
-	"github.com/seaweedfs/fuse"
-	"github.com/seaweedfs/fuse/fs"
 	"context"
 	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/filer2"
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/seaweedfs/fuse"
+	"github.com/seaweedfs/fuse/fs"
 	"net/http"
 	"strings"
 	"sync"
@@ -58,7 +58,11 @@ func (fh *FileHandle) Read(ctx context.Context, req *fuse.ReadRequest, resp *fus
 
 	buff := make([]byte, req.Size)
 
-	chunkViews := filer2.ViewFromChunks(fh.f.entry.Chunks, req.Offset, req.Size)
+	if fh.f.entryViewCache == nil {
+		fh.f.entryViewCache = filer2.NonOverlappingVisibleIntervals(fh.f.entry.Chunks)
+	}
+
+	chunkViews := filer2.ViewFromVisibleIntervals(fh.f.entryViewCache, req.Offset, req.Size)
 
 	var vids []string
 	for _, chunkView := range chunkViews {
@@ -154,6 +158,7 @@ func (fh *FileHandle) Write(ctx context.Context, req *fuse.WriteRequest, resp *f
 
 	for _, chunk := range chunks {
 		fh.f.entry.Chunks = append(fh.f.entry.Chunks, chunk)
+		fh.f.entryViewCache = nil
 		glog.V(1).Infof("uploaded %s/%s to %s [%d,%d)", fh.f.dir.Path, fh.f.Name, chunk.FileId, chunk.Offset, chunk.Offset+int64(chunk.Size))
 		fh.dirtyMetadata = true
 	}
@@ -188,6 +193,7 @@ func (fh *FileHandle) Flush(ctx context.Context, req *fuse.FlushRequest) error {
 	}
 	if chunk != nil {
 		fh.f.entry.Chunks = append(fh.f.entry.Chunks, chunk)
+		fh.f.entryViewCache = nil
 	}
 
 	if !fh.dirtyMetadata {