diff --git a/weed/filer2/filechunks.go b/weed/filer2/filechunks.go
index 7fd4af5df..79aa50ec8 100644
--- a/weed/filer2/filechunks.go
+++ b/weed/filer2/filechunks.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"hash/fnv"
 	"sort"
+	"sync"
 
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 )
@@ -46,6 +47,8 @@ func CompactFileChunks(chunks []*filer_pb.FileChunk) (compacted, garbage []*file
 		}
 	}
 
+	cleanupIntervals(visibles)
+
 	return
 }
 
@@ -89,6 +92,8 @@ func ViewFromChunks(chunks []*filer_pb.FileChunk, offset int64, size int) (views
 		}
 	}
 
+	cleanupIntervals(visibles)
+
 	return views
 
 }
@@ -102,6 +107,12 @@ func logPrintf(name string, visibles []*visibleInterval) {
 	*/
 }
 
+var bufPool = sync.Pool{
+	New: func() interface{} {
+		return new(visibleInterval)
+	},
+}
+
 func mergeIntoVisibles(visibles []*visibleInterval, chunk *filer_pb.FileChunk) (newVisibles []*visibleInterval) {
 	for _, v := range visibles {
 		if v.start < chunk.Offset && chunk.Offset < v.stop {
@@ -153,6 +164,12 @@ func nonOverlappingVisibleIntervals(chunks []*filer_pb.FileChunk) (visibles []*v
 	return
 }
 
+func cleanupIntervals(visibles []*visibleInterval) {
+	for _, v := range visibles {
+		bufPool.Put(v)
+	}
+}
+
 // find non-overlapping visible intervals
 // visible interval map to one file chunk
 
@@ -164,7 +181,12 @@ type visibleInterval struct {
 }
 
 func newVisibleInterval(start, stop int64, fileId string, modifiedTime int64) *visibleInterval {
-	return &visibleInterval{start: start, stop: stop, fileId: fileId, modifiedTime: modifiedTime}
+	b := bufPool.Get().(*visibleInterval)
+	b.start = start
+	b.stop = stop
+	b.fileId = fileId
+	b.modifiedTime = modifiedTime
+	return b
 }
 
 func min(x, y int64) int64 {
diff --git a/weed/filer2/filechunks_test.go b/weed/filer2/filechunks_test.go
index 90aa3df36..1b124981f 100644
--- a/weed/filer2/filechunks_test.go
+++ b/weed/filer2/filechunks_test.go
@@ -161,6 +161,9 @@ func TestIntervalMerging(t *testing.T) {
 		if len(intervals) != len(testcase.Expected) {
 			t.Fatalf("failed to compact test case %d, len %d expected %d", i, len(intervals), len(testcase.Expected))
 		}
+
+		cleanupIntervals(intervals)
+
 	}
 
 }
diff --git a/weed/filer2/filer.go b/weed/filer2/filer.go
index 1c9f2cde4..f6f013933 100644
--- a/weed/filer2/filer.go
+++ b/weed/filer2/filer.go
@@ -3,6 +3,7 @@ package filer2
 import (
 	"context"
 	"fmt"
+	"math"
 	"os"
 	"path/filepath"
 	"strings"
@@ -13,7 +14,7 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/wdclient"
 	"github.com/karlseguin/ccache"
-	"math"
+	"github.com/chrislusf/seaweedfs/weed/storage"
 )
 
 type Filer struct {
@@ -240,7 +241,7 @@ func (f *Filer) DeleteFileByFileId(fileId string) {
 	if err != nil {
 		glog.V(0).Infof("can not find file %s: %v", fileId, err)
 	}
-	if _, err := operation.DeleteFilesAtOneVolumeServer(volumeServer, []string{fileId}); err != nil {
+	if _, err := operation.DeleteFilesAtOneVolumeServer(volumeServer, []string{fileId}); err != nil && err != storage.NotFound{
 		glog.V(0).Infof("deleting file %s: %v", fileId, err)
 	}
 }
diff --git a/weed/filesys/filehandle.go b/weed/filesys/filehandle.go
index 78ae5d342..c640755ee 100644
--- a/weed/filesys/filehandle.go
+++ b/weed/filesys/filehandle.go
@@ -188,8 +188,8 @@ func (fh *FileHandle) Flush(ctx context.Context, req *fuse.FlushRequest) error {
 
 	chunk, err := fh.dirtyPages.FlushToStorage(ctx)
 	if err != nil {
-		glog.Errorf("flush %s/%s to %s [%d,%d): %v", fh.f.dir.Path, fh.f.Name, chunk.FileId, chunk.Offset, chunk.Offset+int64(chunk.Size), err)
-		return fmt.Errorf("flush %s/%s to %s [%d,%d): %v", fh.f.dir.Path, fh.f.Name, chunk.FileId, chunk.Offset, chunk.Offset+int64(chunk.Size), err)
+		glog.Errorf("flush %s/%s: %v", fh.f.dir.Path, fh.f.Name, err)
+		return fmt.Errorf("flush %s/%s: %v", fh.f.dir.Path, fh.f.Name, err)
 	}
 	if chunk != nil {
 		fh.f.entry.Chunks = append(fh.f.entry.Chunks, chunk)
diff --git a/weed/operation/delete_content.go b/weed/operation/delete_content.go
index 72041f126..806bfbe7b 100644
--- a/weed/operation/delete_content.go
+++ b/weed/operation/delete_content.go
@@ -105,7 +105,7 @@ func DeleteFilesAtOneVolumeServer(volumeServer string, fileIds []string) (ret []
 
 		resp, err := volumeServerClient.BatchDelete(context.Background(), req)
 
-		fmt.Printf("deleted %v %v: %v\n", fileIds, err, resp)
+		// fmt.Printf("deleted %v %v: %v\n", fileIds, err, resp)
 
 		if err != nil {
 			return err
@@ -121,7 +121,7 @@ func DeleteFilesAtOneVolumeServer(volumeServer string, fileIds []string) (ret []
 	}
 
 	for _, result := range ret {
-		if result.Error != "" {
+		if result.Error != "" && result.Error != "Not Found" {
 			return nil, fmt.Errorf("delete fileId %s: %v", result.FileId, result.Error)
 		}
 	}
diff --git a/weed/topology/cluster_commands.go b/weed/topology/cluster_commands.go
index bb44669b2..7a36c25ec 100644
--- a/weed/topology/cluster_commands.go
+++ b/weed/topology/cluster_commands.go
@@ -25,7 +25,7 @@ func (c *MaxVolumeIdCommand) Apply(server raft.Server) (interface{}, error) {
 	before := topo.GetMaxVolumeId()
 	topo.UpAdjustMaxVolumeId(c.MaxVolumeId)
 
-	glog.V(0).Infoln("max volume id", before, "==>", topo.GetMaxVolumeId())
+	glog.V(1).Infoln("max volume id", before, "==>", topo.GetMaxVolumeId())
 
 	return nil, nil
 }