diff --git a/README.md b/README.md
index be637340a..7ef2a72b8 100644
--- a/README.md
+++ b/README.md
@@ -301,58 +301,55 @@ POSIX support
 
 ## Benchmark
 
-My Own Unscientific Single Machine Results on Mac Book with Solid State Disk, CPU: 1 Intel Core i7 2.2GHz.
+My Own Unscientific Single Machine Results on Mac Book with Solid State Disk, CPU: 1 Intel Core i7 2.6GHz.
 
 Write 1 million 1KB file:
 ```
-Concurrency Level:      64
-Time taken for tests:   182.456 seconds
+Concurrency Level:      16
+Time taken for tests:   88.796 seconds
 Complete requests:      1048576
 Failed requests:        0
-Total transferred:      1073741824 bytes
-Requests per second:    5747.01 [#/sec]
-Transfer rate:          5747.01 [Kbytes/sec]
+Total transferred:      1106764659 bytes
+Requests per second:    11808.87 [#/sec]
+Transfer rate:          12172.05 [Kbytes/sec]
 
 Connection Times (ms)
               min      avg        max      std
-Total:        0.3      10.9       430.9      5.7
+Total:        0.2      1.3       44.8      0.9
 
 Percentage of the requests served within a certain time (ms)
-   50%     10.2 ms
-   66%     12.0 ms
-   75%     12.6 ms
-   80%     12.9 ms
-   90%     14.0 ms
-   95%     14.9 ms
-   98%     16.2 ms
-   99%     17.3 ms
-  100%    430.9 ms
+   50%      1.1 ms
+   66%      1.3 ms
+   75%      1.5 ms
+   80%      1.7 ms
+   90%      2.1 ms
+   95%      2.6 ms
+   98%      3.7 ms
+   99%      4.6 ms
+  100%     44.8 ms
 ```
 
 Randomly read 1 million files:
 ```
-Concurrency Level:      64
-Time taken for tests:   80.732 seconds
+Concurrency Level:      16
+Time taken for tests:   34.263 seconds
 Complete requests:      1048576
 Failed requests:        0
-Total transferred:      1073741824 bytes
-Requests per second:    12988.37 [#/sec]
-Transfer rate:          12988.37 [Kbytes/sec]
+Total transferred:      1106762945 bytes
+Requests per second:    30603.34 [#/sec]
+Transfer rate:          31544.49 [Kbytes/sec]
 
 Connection Times (ms)
               min      avg        max      std
-Total:        0.0      4.7       254.3      6.3
+Total:        0.0      0.5       20.7      0.7
 
 Percentage of the requests served within a certain time (ms)
-   50%      2.6 ms
-   66%      2.9 ms
-   75%      3.7 ms
-   80%      4.7 ms
-   90%     10.3 ms
-   95%     16.6 ms
-   98%     26.3 ms
-   99%     34.8 ms
-  100%    254.3 ms
+   50%      0.4 ms
+   75%      0.5 ms
+   95%      0.6 ms
+   98%      0.8 ms
+   99%      1.2 ms
+  100%     20.7 ms
 ```
 
 
diff --git a/go/storage/needle_read_write.go b/go/storage/needle_read_write.go
index 9a9f63ddb..eb2d8d459 100644
--- a/go/storage/needle_read_write.go
+++ b/go/storage/needle_read_write.go
@@ -120,7 +120,7 @@ func (n *Needle) Append(w io.Writer, version Version) (size uint32, err error) {
 					return
 				}
 			}
-			if n.HasTtl() {
+			if n.HasTtl() && n.Ttl != nil {
 				n.Ttl.ToBytes(header[0:TtlBytesLength])
 				if _, err = w.Write(header[0:TtlBytesLength]); err != nil {
 					return
diff --git a/go/storage/volume.go b/go/storage/volume.go
index 0e6cadecc..998b0dd64 100644
--- a/go/storage/volume.go
+++ b/go/storage/volume.go
@@ -152,6 +152,9 @@ func (v *Volume) NeedToReplicate() bool {
 // isFileUnchanged checks whether this needle to write is same as last one.
 // It requires serialized access in the same volume.
 func (v *Volume) isFileUnchanged(n *Needle) bool {
+	if v.Ttl == EMPTY_TTL || v.Ttl.String() == "" {
+		return true
+	}
 	nv, ok := v.nm.Get(n.Id)
 	if ok && nv.Offset > 0 {
 		oldNeedle := new(Needle)
diff --git a/go/weed/export.go b/go/weed/export.go
index 963d2aaba..4417c65f4 100644
--- a/go/weed/export.go
+++ b/go/weed/export.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"text/template"
@@ -49,7 +50,7 @@ func init() {
 
 var (
 	output = cmdExport.Flag.String("o", "", "output tar file name, must ends with .tar, or just a \"-\" for stdout")
-	format = cmdExport.Flag.String("fileNameFormat", defaultFnFormat, "filename format, default to {{.Mime}}/{{.Id}}:{{.Name}}")
+	format = cmdExport.Flag.String("fileNameFormat", defaultFnFormat, "filename formatted with {{.Mime}} {{.Id}} {{.Name}} {{.Ext}}")
 	newer  = cmdExport.Flag.String("newer", "", "export only files newer than this time, default is all files. Must be specified in RFC3339 without timezone")
 
 	tarOutputFile          *tar.Writer
@@ -159,6 +160,7 @@ type nameParams struct {
 	Id   uint64
 	Mime string
 	Key  string
+	Ext  string
 }
 
 func walker(vid storage.VolumeId, n *storage.Needle, version storage.Version) (err error) {
@@ -166,10 +168,12 @@ func walker(vid storage.VolumeId, n *storage.Needle, version storage.Version) (e
 	if tarOutputFile != nil {
 		fileNameTemplateBuffer.Reset()
 		if err = fileNameTemplate.Execute(fileNameTemplateBuffer,
-			nameParams{Name: string(n.Name),
+			nameParams{
+				Name: string(n.Name),
 				Id:   n.Id,
 				Mime: string(n.Mime),
 				Key:  key,
+				Ext:  filepath.Ext(string(n.Name)),
 			},
 		); err != nil {
 			return err