diff --git a/weed-fs/src/cmd/weedmaster/weedmaster.go b/weed-fs/src/cmd/weedmaster/weedmaster.go
index b41a5d437..13733f2ca 100644
--- a/weed-fs/src/cmd/weedmaster/weedmaster.go
+++ b/weed-fs/src/cmd/weedmaster/weedmaster.go
@@ -74,7 +74,8 @@ func writeJson(w http.ResponseWriter, r *http.Request, obj interface{}) {
 
 func main() {
 	flag.Parse()
-	mapper = directory.NewMapper(*metaFolder, "directory", uint32(*volumeSizeLimitMB*1024*1024))
+    log.Println("Volume Size Limit is", *volumeSizeLimitMB, "MB")
+	mapper = directory.NewMapper(*metaFolder, "directory", uint64(*volumeSizeLimitMB)*1024*1024)
 	http.HandleFunc("/dir/assign", dirAssignHandler)
 	http.HandleFunc("/dir/lookup", dirLookupHandler)
 	http.HandleFunc("/dir/join", dirJoinHandler)
diff --git a/weed-fs/src/cmd/weedvolume/weedvolume.go b/weed-fs/src/cmd/weedvolume/weedvolume.go
index 88ad01c0d..b026189c0 100644
--- a/weed-fs/src/cmd/weedvolume/weedvolume.go
+++ b/weed-fs/src/cmd/weedvolume/weedvolume.go
@@ -1,157 +1,168 @@
 package main
 
 import (
-    "storage"
-    "flag"
-    "fmt"
-    "http"
-    "json"
-    "log"
-    "mime"
-    "rand"
-    "strconv"
-    "strings"
-    "time"
+	"storage"
+	"flag"
+	"fmt"
+	"http"
+	"json"
+	"log"
+	"mime"
+	"rand"
+	"strconv"
+	"strings"
+	"time"
 )
 
 var (
-    port         = flag.Int("port", 8080, "http listen port")
-    chunkFolder  = flag.String("dir", "/tmp", "data directory to store files")
-    volumes   = flag.String("volumes", "0,1-3,4", "comma-separated list of volume ids or range of ids")
-    publicUrl = flag.String("publicUrl", "localhost:8080", "public url to serve data read")
-    metaServer   = flag.String("mserver", "localhost:9333", "master directory server to store mappings")
-    IsDebug      = flag.Bool("debug", false, "enable debug mode")
-    pulse        = flag.Int("pulseSeconds", 5, "number of seconds between heartbeats")
+	port        = flag.Int("port", 8080, "http listen port")
+	chunkFolder = flag.String("dir", "/tmp", "data directory to store files")
+	volumes     = flag.String("volumes", "0,1-3,4", "comma-separated list of volume ids or range of ids")
+	publicUrl   = flag.String("publicUrl", "localhost:8080", "public url to serve data read")
+	metaServer  = flag.String("mserver", "localhost:9333", "master directory server to store mappings")
+	IsDebug     = flag.Bool("debug", false, "enable debug mode")
+	pulse       = flag.Int("pulseSeconds", 5, "number of seconds between heartbeats")
 
-    store *storage.Store
+	store *storage.Store
 )
 
 func statusHandler(w http.ResponseWriter, r *http.Request) {
-    writeJson(w, r, store.Status())
+	writeJson(w, r, store.Status())
 }
 func addVolumeHandler(w http.ResponseWriter, r *http.Request) {
-    store.AddVolume(r.FormValue("volume"))
-    writeJson(w, r, store.Status())
+	store.AddVolume(r.FormValue("volume"))
+	writeJson(w, r, store.Status())
 }
 func storeHandler(w http.ResponseWriter, r *http.Request) {
-    switch r.Method {
-    case "GET":
-        GetHandler(w, r)
-    case "DELETE":
-        DeleteHandler(w, r)
-    case "POST":
-        PostHandler(w, r)
-    }
+	switch r.Method {
+	case "GET":
+		GetHandler(w, r)
+	case "DELETE":
+		DeleteHandler(w, r)
+	case "POST":
+		PostHandler(w, r)
+	}
 }
 func GetHandler(w http.ResponseWriter, r *http.Request) {
-    n := new(storage.Needle)
-    vid, fid, ext := parseURLPath(r.URL.Path)
-    volumeId, _ := strconv.Atoui64(vid)
-    n.ParsePath(fid)
+	n := new(storage.Needle)
+	vid, fid, ext := parseURLPath(r.URL.Path)
+	volumeId, _ := strconv.Atoui64(vid)
+	n.ParsePath(fid)
 
-    if *IsDebug {
-        log.Println("volume", volumeId, "reading", n)
-    }
-    cookie := n.Cookie
-    count, e := store.Read(volumeId, n)
-    if *IsDebug {
-        log.Println("read bytes", count, "error", e)
-    }
-    if n.Cookie != cookie {
-        log.Println("request with unmaching cookie from ", r.RemoteAddr, "agent", r.UserAgent())
-        return
-    }
-    if ext != "" {
-        w.Header().Set("Content-Type", mime.TypeByExtension(ext))
-    }
-    w.Write(n.Data)
+	if *IsDebug {
+		log.Println("volume", volumeId, "reading", n)
+	}
+	cookie := n.Cookie
+	count, e := store.Read(volumeId, n)
+	if *IsDebug {
+		log.Println("read bytes", count, "error", e)
+	}
+	if n.Cookie != cookie {
+		log.Println("request with unmaching cookie from ", r.RemoteAddr, "agent", r.UserAgent())
+		return
+	}
+	if ext != "" {
+		w.Header().Set("Content-Type", mime.TypeByExtension(ext))
+	}
+	w.Write(n.Data)
 }
 func PostHandler(w http.ResponseWriter, r *http.Request) {
-    vid, _, _ := parseURLPath(r.URL.Path)
-    volumeId, e := strconv.Atoui64(vid)
-    if e != nil {
-        writeJson(w, r, e)
-    } else {
-        ret := store.Write(volumeId, storage.NewNeedle(r))
-        m := make(map[string]uint32)
-        m["size"] = ret
-        writeJson(w, r, m)
-    }
+	vid, _, _ := parseURLPath(r.URL.Path)
+	volumeId, e := strconv.Atoui64(vid)
+	if e != nil {
+		writeJson(w, r, e)
+	} else {
+		ret := store.Write(volumeId, storage.NewNeedle(r))
+		m := make(map[string]uint32)
+		m["size"] = ret
+		writeJson(w, r, m)
+	}
 }
 func DeleteHandler(w http.ResponseWriter, r *http.Request) {
-    n := new(storage.Needle)
-    vid, fid, _ := parseURLPath(r.URL.Path)
-    volumeId, _ := strconv.Atoui64(vid)
-    n.ParsePath(fid)
+	n := new(storage.Needle)
+	vid, fid, _ := parseURLPath(r.URL.Path)
+	volumeId, _ := strconv.Atoui64(vid)
+	n.ParsePath(fid)
 
-    cookie := n.Cookie
-    count, _ := store.Read(volumeId, n)
+	if *IsDebug {
+		log.Println("deleting", n)
+	}
 
-    if n.Cookie != cookie {
-        log.Println("delete with unmaching cookie from ", r.RemoteAddr, "agent", r.UserAgent())
-        return
-    }
+	cookie := n.Cookie
+	count, ok := store.Read(volumeId, n)
 
-    n.Size = 0
-    store.Write(volumeId, n)
-    m := make(map[string]uint32)
-    m["size"] = uint32(count)
-    writeJson(w, r, m)
+	if ok!=nil {
+		m := make(map[string]uint32)
+		m["size"] = 0
+		writeJson(w, r, m)
+		return
+	}
+
+	if n.Cookie != cookie {
+		log.Println("delete with unmaching cookie from ", r.RemoteAddr, "agent", r.UserAgent())
+		return
+	}
+
+	n.Size = 0
+	store.Delete(volumeId, n)
+	m := make(map[string]uint32)
+	m["size"] = uint32(count)
+	writeJson(w, r, m)
 }
 func writeJson(w http.ResponseWriter, r *http.Request, obj interface{}) {
-    w.Header().Set("Content-Type", "application/javascript")
-    bytes, _ := json.Marshal(obj)
-    callback := r.FormValue("callback")
-    if callback == "" {
-        w.Write(bytes)
-    } else {
-        w.Write([]uint8(callback))
-        w.Write([]uint8("("))
-        fmt.Fprint(w, string(bytes))
-        w.Write([]uint8(")"))
-    }
-    //log.Println("JSON Response", string(bytes))
+	w.Header().Set("Content-Type", "application/javascript")
+	bytes, _ := json.Marshal(obj)
+	callback := r.FormValue("callback")
+	if callback == "" {
+		w.Write(bytes)
+	} else {
+		w.Write([]uint8(callback))
+		w.Write([]uint8("("))
+		fmt.Fprint(w, string(bytes))
+		w.Write([]uint8(")"))
+	}
+	//log.Println("JSON Response", string(bytes))
 }
 func parseURLPath(path string) (vid, fid, ext string) {
-    sepIndex := strings.LastIndex(path, "/")
-    commaIndex := strings.LastIndex(path[sepIndex:], ",")
-    if commaIndex <= 0 {
-        log.Println("unknown file id", path[sepIndex+1:])
-        return
-    }
-    dotIndex := strings.LastIndex(path[sepIndex:], ".")
-    vid = path[sepIndex+1 : commaIndex]
-    fid = path[commaIndex+1:]
-    ext = ""
-    if dotIndex > 0 {
-        fid = path[commaIndex+1 : dotIndex]
-        ext = path[dotIndex+1:]
-    }
-    return
+	sepIndex := strings.LastIndex(path, "/")
+	commaIndex := strings.LastIndex(path[sepIndex:], ",")
+	if commaIndex <= 0 {
+		log.Println("unknown file id", path[sepIndex+1:])
+		return
+	}
+	dotIndex := strings.LastIndex(path[sepIndex:], ".")
+	vid = path[sepIndex+1 : commaIndex]
+	fid = path[commaIndex+1:]
+	ext = ""
+	if dotIndex > 0 {
+		fid = path[commaIndex+1 : dotIndex]
+		ext = path[dotIndex+1:]
+	}
+	return
 }
 
 func main() {
-    flag.Parse()
-    //TODO: now default to 1G, this value should come from server?
-    store = storage.NewStore(*port, *publicUrl, *chunkFolder, *volumes)
-    defer store.Close()
-    http.HandleFunc("/", storeHandler)
-    http.HandleFunc("/status", statusHandler)
-    http.HandleFunc("/add_volume", addVolumeHandler)
+	flag.Parse()
+	//TODO: now default to 1G, this value should come from server?
+	store = storage.NewStore(*port, *publicUrl, *chunkFolder, *volumes)
+	defer store.Close()
+	http.HandleFunc("/", storeHandler)
+	http.HandleFunc("/status", statusHandler)
+	http.HandleFunc("/add_volume", addVolumeHandler)
 
-    go func() {
-        for {
-            store.Join(*metaServer)
-            ns := int64(*pulse) * 1e9
-            time.Sleep(ns + rand.Int63()%ns)
-        }
-    }()
-    log.Println("store joined at", *metaServer)
+	go func() {
+		for {
+			store.Join(*metaServer)
+			ns := int64(*pulse) * 1e9
+			time.Sleep(ns + rand.Int63()%ns)
+		}
+	}()
+	log.Println("store joined at", *metaServer)
 
-    log.Println("Start storage service at http://127.0.0.1:" + strconv.Itoa(*port), "public url", *publicUrl)
-    e := http.ListenAndServe(":"+strconv.Itoa(*port), nil)
-    if e != nil {
-        log.Fatalf("Fail to start:", e.String())
-    }
+	log.Println("Start storage service at http://127.0.0.1:"+strconv.Itoa(*port), "public url", *publicUrl)
+	e := http.ListenAndServe(":"+strconv.Itoa(*port), nil)
+	if e != nil {
+		log.Fatalf("Fail to start:", e.String())
+	}
 
 }
diff --git a/weed-fs/src/pkg/directory/volume_mapping.go b/weed-fs/src/pkg/directory/volume_mapping.go
index b4862d70f..0db282d5c 100644
--- a/weed-fs/src/pkg/directory/volume_mapping.go
+++ b/weed-fs/src/pkg/directory/volume_mapping.go
@@ -36,14 +36,14 @@ type Mapper struct {
 	FileIdSequence uint64
 	fileIdCounter  uint64
 
-	volumeSizeLimit uint32
+	volumeSizeLimit uint64
 }
 
 func NewMachine(server, publicUrl string, volumes []storage.VolumeInfo) *Machine {
 	return &Machine{Server: MachineInfo{Url: server, PublicUrl: publicUrl}, Volumes: volumes}
 }
 
-func NewMapper(dirname string, filename string, volumeSizeLimit uint32) (m *Mapper) {
+func NewMapper(dirname string, filename string, volumeSizeLimit uint64) (m *Mapper) {
 	m = &Mapper{dir: dirname, fileName: filename}
 	m.vid2machineId = make(map[uint32]int)
 	m.volumeSizeLimit = volumeSizeLimit
@@ -96,6 +96,7 @@ func (m *Mapper) Get(vid uint32) (*Machine, os.Error) {
 }
 func (m *Mapper) Add(machine Machine) {
 	//check existing machine, linearly
+    log.Println("Adding machine", machine.Server.Url)
 	m.lock.Lock()
 	foundExistingMachineId := -1
 	for index, entry := range m.Machines {
@@ -115,14 +116,13 @@ func (m *Mapper) Add(machine Machine) {
 
 	//add to vid2machineId map, and Writers array
 	for _, v := range machine.Volumes {
-		//log.Println("Setting volume", v.Id, "to", machine.Server.Url)
 		m.vid2machineId[v.Id] = machineId + 1 //use base 1 indexed, to detect not found cases
 	}
-	//setting Writers, copy-on-write because of possible updating
+	//setting Writers, copy-on-write because of possible updating, this needs some future work!
 	var writers []uint32
 	for _, machine_entry := range m.Machines {
 		for _, v := range machine_entry.Volumes {
-			if v.Size < int64(m.volumeSizeLimit) {
+			if uint64(v.Size) < m.volumeSizeLimit {
 				writers = append(writers, v.Id)
 			}
 		}
diff --git a/weed-fs/src/pkg/storage/store.go b/weed-fs/src/pkg/storage/store.go
index 221e9f565..f70321ab1 100644
--- a/weed-fs/src/pkg/storage/store.go
+++ b/weed-fs/src/pkg/storage/store.go
@@ -92,7 +92,10 @@ func (s *Store) Close() {
 	}
 }
 func (s *Store) Write(i uint64, n *Needle) uint32 {
-	return s.volumes[i].write(n)
+    return s.volumes[i].write(n)
+}
+func (s *Store) Delete(i uint64, n *Needle) uint32 {
+	return s.volumes[i].delete(n)
 }
 func (s *Store) Read(i uint64, n *Needle) (int, os.Error) {
 	return s.volumes[i].read(n)
diff --git a/weed-fs/src/pkg/storage/volume.go b/weed-fs/src/pkg/storage/volume.go
index 438a0f56e..08c97af9d 100644
--- a/weed-fs/src/pkg/storage/volume.go
+++ b/weed-fs/src/pkg/storage/volume.go
@@ -9,7 +9,7 @@ import (
 )
 
 const (
-    SuperBlockSize = 8
+	SuperBlockSize = 8
 )
 
 type Volume struct {
@@ -69,6 +69,19 @@ func (v *Volume) write(n *Needle) uint32 {
 	}
 	return ret
 }
+func (v *Volume) delete(n *Needle) uint32 {
+	v.accessLock.Lock()
+	defer v.accessLock.Unlock()
+	nv, ok := v.nm.Get(n.Key)
+	//log.Println("key", n.Key, "volume offset", nv.Offset, "data_size", n.Size, "cached size", nv.Size)
+	if ok {
+		v.nm.Delete(n.Key)
+		v.dataFile.Seek(int64(nv.Offset*8), 0)
+		n.Append(v.dataFile)
+		return nv.Size
+	}
+	return 0
+}
 func (v *Volume) read(n *Needle) (int, os.Error) {
 	v.accessLock.Lock()
 	defer v.accessLock.Unlock()
@@ -79,8 +92,3 @@ func (v *Volume) read(n *Needle) (int, os.Error) {
 	}
 	return -1, os.EOF
 }
-func (v *Volume) delete(n *Needle) {
-    v.accessLock.Lock()
-    defer v.accessLock.Unlock()
-    v.nm.Delete(n.Key)
-}