diff --git a/.github/workflows/cleanup.yml b/.github/workflows/cleanup.yml
new file mode 100644
index 000000000..47a677e6d
--- /dev/null
+++ b/.github/workflows/cleanup.yml
@@ -0,0 +1,22 @@
+name: Cleanup
+
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+
+    steps:
+
+      - name: Delete old release assets
+        uses: mknejp/delete-release-assets@v1
+        with:
+          token: ${{ github.token }}
+          tag: dev
+          fail-if-no-assets: false
+          assets: |
+            weed-*
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 7439fb604..0681f3dac 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -13,7 +13,7 @@ jobs:
       matrix:
         goos: [linux, windows, darwin, freebsd ]
         goarch: [amd64, arm]
-        exclude:  
+        exclude:
           - goarch: arm
             goos: darwin
           - goarch: arm
@@ -21,46 +21,42 @@ jobs:
 
     steps:
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v2
 
-    - name: Delete old release assets
-      uses: mknejp/delete-release-assets@v1
-      with:
-        token: ${{ github.token }}
-        tag: dev
-        fail-if-no-assets: false 
-        assets: | 
-          weed-*
+      - name: Wait for the deletion
+        uses: jakejarvis/wait-action@master
+        with:
+          time: '30s'
 
-    - name: Set BUILD_TIME env
-      run: echo BUILD_TIME=$(date -u +%Y-%m-%d-%H-%M) >> ${GITHUB_ENV}
+      - name: Set BUILD_TIME env
+        run: echo BUILD_TIME=$(date -u +%Y-%m-%d-%H-%M) >> ${GITHUB_ENV}
 
-    - name: Go Release Binaries
-      uses: wangyoucao577/go-release-action@v1.14
-      with:
-        github_token: ${{ secrets.GITHUB_TOKEN }}
-        goos: ${{ matrix.goos }}
-        goarch: ${{ matrix.goarch }}
-        release_tag: dev
-        overwrite: true 
-        build_flags: -tags 5BytesOffset # optional, default is 
-        ldflags: -extldflags -static -X github.com/chrislusf/seaweedfs/weed/util.COMMIT=${{github.sha}}
-        # Where to run `go build .`
-        project_path: weed
-        binary_name: weed-large-disk
-        asset_name: "weed-large-disk-${{ env.BUILD_TIME }}-${{ matrix.goos }}-${{ matrix.goarch }}"
+      - name: Go Release Binaries
+        uses: wangyoucao577/go-release-action@v1.14
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          goos: ${{ matrix.goos }}
+          goarch: ${{ matrix.goarch }}
+          release_tag: dev
+          overwrite: true
+          build_flags: -tags 5BytesOffset # optional, default is
+          ldflags: -extldflags -static -X github.com/chrislusf/seaweedfs/weed/util.COMMIT=${{github.sha}}
+          # Where to run `go build .`
+          project_path: weed
+          binary_name: weed-large-disk
+          asset_name: "weed-large-disk-${{ env.BUILD_TIME }}-${{ matrix.goos }}-${{ matrix.goarch }}"
 
-    - name: Go Release Binaries
-      uses: wangyoucao577/go-release-action@v1.14
-      with:
-        github_token: ${{ secrets.GITHUB_TOKEN }}
-        goos: ${{ matrix.goos }}
-        goarch: ${{ matrix.goarch }}
-        release_tag: dev
-        overwrite: true 
-        ldflags: -extldflags -static -X github.com/chrislusf/seaweedfs/weed/util.COMMIT=${{github.sha}}
-        # Where to run `go build .`
-        project_path: weed
-        binary_name: weed-
-        asset_name: "weed-${{ env.BUILD_TIME }}-${{ matrix.goos }}-${{ matrix.goarch }}"
+      - name: Go Release Binaries
+        uses: wangyoucao577/go-release-action@v1.14
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          goos: ${{ matrix.goos }}
+          goarch: ${{ matrix.goarch }}
+          release_tag: dev
+          overwrite: true
+          ldflags: -extldflags -static -X github.com/chrislusf/seaweedfs/weed/util.COMMIT=${{github.sha}}
+          # Where to run `go build .`
+          project_path: weed
+          binary_name: weed-
+          asset_name: "weed-${{ env.BUILD_TIME }}-${{ matrix.goos }}-${{ matrix.goarch }}"
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 528a52609..6309e7e2e 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,5 +1,7 @@
 FROM alpine
 
+ARG RELEASE=latest # 'latest' or 'dev'
+
 RUN \
     ARCH=$(if [ $(uname -m) == "x86_64" ] && [ $(getconf LONG_BIT) == "64" ]; then echo "amd64"; \
          elif [ $(uname -m) == "x86_64" ] && [ $(getconf LONG_BIT) == "32" ]; then echo "386"; \
@@ -13,7 +15,7 @@ RUN \
     # Install SeaweedFS and Supercronic ( for cron job mode )
     apk add --no-cache --virtual build-dependencies --update wget curl ca-certificates && \
     apk add fuse && \
-    wget -P /tmp https://github.com/$(curl -s -L https://github.com/chrislusf/seaweedfs/releases/latest | egrep -o "chrislusf/seaweedfs/releases/download/.*/linux_$ARCH.tar.gz") && \
+    wget -P /tmp https://github.com/$(curl -s -L https://github.com/chrislusf/seaweedfs/releases/${RELEASE} | egrep -o "chrislusf/seaweedfs/releases/download/.*/linux_$ARCH.tar.gz") && \
     tar -C /usr/bin/ -xzvf /tmp/linux_$ARCH.tar.gz && \
     curl -fsSLO "$SUPERCRONIC_URL" && \
     echo "${SUPERCRONIC_SHA1SUM}  ${SUPERCRONIC}" | sha1sum -c - && \
diff --git a/docker/compose/local-mount-compose.yml b/docker/compose/local-mount-compose.yml
index 4361d6d99..b1c579cdf 100644
--- a/docker/compose/local-mount-compose.yml
+++ b/docker/compose/local-mount-compose.yml
@@ -30,7 +30,7 @@ services:
   mount_1:
     image: chrislusf/seaweedfs:local
     privileged: true
-    entrypoint: '/bin/sh -c "mkdir -p t1 && mkdir -p cache/t1 && weed -v=4 mount -filer=filer:8888 -cacheDir=./cache/t1 -dir=./t1 -filer.path=/c1" -volumeServerAccess=filerProxy'
+    entrypoint: '/bin/sh -c "mkdir -p t1 && mkdir -p cache/t1 && weed -v=4 mount -filer=filer:8888 -cacheDir=./cache/t1 -dir=./t1 -filer.path=/c1 -volumeServerAccess=filerProxy"'
     depends_on:
       - master
       - volume
@@ -38,7 +38,7 @@ services:
   mount_2:
     image: chrislusf/seaweedfs:local
     privileged: true
-    entrypoint: '/bin/sh -c "mkdir -p t2 && mkdir -p cache/t2 && weed -v=4  mount -filer=filer:8888 -cacheDir=./cache/t2 -dir=./t2 -filer.path=/c1" -volumeServerAcess=publicUrl'
+    entrypoint: '/bin/sh -c "mkdir -p t2 && mkdir -p cache/t2 && weed -v=4  mount -filer=filer:8888 -cacheDir=./cache/t2 -dir=./t2 -filer.path=/c1 -volumeServerAcess=publicUrl"'
     depends_on:
       - master
       - volume
diff --git a/weed/command/filer.go b/weed/command/filer.go
index 7f665cec8..6660bd694 100644
--- a/weed/command/filer.go
+++ b/weed/command/filer.go
@@ -52,7 +52,7 @@ type FilerOptions struct {
 func init() {
 	cmdFiler.Run = runFiler // break init cycle
 	f.masters = cmdFiler.Flag.String("master", "localhost:9333", "comma-separated master servers")
-	f.collection = cmdFiler.Flag.String("collection", "", "all data will be stored in this collection")
+	f.collection = cmdFiler.Flag.String("collection", "", "all data will be stored in this default collection")
 	f.ip = cmdFiler.Flag.String("ip", util.DetectedHostAddress(), "filer server http listen ip address")
 	f.bindIp = cmdFiler.Flag.String("ip.bind", "0.0.0.0", "ip address to bind to")
 	f.port = cmdFiler.Flag.Int("port", 8888, "filer server http listen port")
@@ -83,6 +83,8 @@ func init() {
 	filerStartWebDav = cmdFiler.Flag.Bool("webdav", false, "whether to start webdav gateway")
 	filerWebDavOptions.port = cmdFiler.Flag.Int("webdav.port", 7333, "webdav server http listen port")
 	filerWebDavOptions.collection = cmdFiler.Flag.String("webdav.collection", "", "collection to create the files")
+	filerWebDavOptions.replication = cmdFiler.Flag.String("webdav.replication", "", "replication to create the files")
+	filerWebDavOptions.disk = cmdFiler.Flag.String("webdav.disk", "", "[hdd|ssd] hard drive or solid state drive")
 	filerWebDavOptions.tlsPrivateKey = cmdFiler.Flag.String("webdav.key.file", "", "path to the TLS private key file")
 	filerWebDavOptions.tlsCertificate = cmdFiler.Flag.String("webdav.cert.file", "", "path to the TLS certificate file")
 	filerWebDavOptions.cacheDir = cmdFiler.Flag.String("webdav.cacheDir", os.TempDir(), "local cache directory for file chunks")
diff --git a/weed/command/server.go b/weed/command/server.go
index 61cac2cc7..d7c41b014 100644
--- a/weed/command/server.go
+++ b/weed/command/server.go
@@ -121,6 +121,8 @@ func init() {
 
 	webdavOptions.port = cmdServer.Flag.Int("webdav.port", 7333, "webdav server http listen port")
 	webdavOptions.collection = cmdServer.Flag.String("webdav.collection", "", "collection to create the files")
+	webdavOptions.replication = cmdServer.Flag.String("webdav.replication", "", "replication to create the files")
+	webdavOptions.disk = cmdServer.Flag.String("webdav.disk", "", "[hdd|ssd] hard drive or solid state drive")
 	webdavOptions.tlsPrivateKey = cmdServer.Flag.String("webdav.key.file", "", "path to the TLS private key file")
 	webdavOptions.tlsCertificate = cmdServer.Flag.String("webdav.cert.file", "", "path to the TLS certificate file")
 	webdavOptions.cacheDir = cmdServer.Flag.String("webdav.cacheDir", os.TempDir(), "local cache directory for file chunks")
diff --git a/weed/command/webdav.go b/weed/command/webdav.go
index dc84b1fd0..3e4532d6e 100644
--- a/weed/command/webdav.go
+++ b/weed/command/webdav.go
@@ -25,6 +25,8 @@ type WebDavOption struct {
 	filer          *string
 	port           *int
 	collection     *string
+	replication    *string
+	disk           *string
 	tlsPrivateKey  *string
 	tlsCertificate *string
 	cacheDir       *string
@@ -36,6 +38,8 @@ func init() {
 	webDavStandaloneOptions.filer = cmdWebDav.Flag.String("filer", "localhost:8888", "filer server address")
 	webDavStandaloneOptions.port = cmdWebDav.Flag.Int("port", 7333, "webdav server http listen port")
 	webDavStandaloneOptions.collection = cmdWebDav.Flag.String("collection", "", "collection to create the files")
+	webDavStandaloneOptions.replication = cmdWebDav.Flag.String("replication", "", "replication to create the files")
+	webDavStandaloneOptions.disk = cmdWebDav.Flag.String("disk", "", "[hdd|ssd] hard drive or solid state drive")
 	webDavStandaloneOptions.tlsPrivateKey = cmdWebDav.Flag.String("key.file", "", "path to the TLS private key file")
 	webDavStandaloneOptions.tlsCertificate = cmdWebDav.Flag.String("cert.file", "", "path to the TLS certificate file")
 	webDavStandaloneOptions.cacheDir = cmdWebDav.Flag.String("cacheDir", os.TempDir(), "local cache directory for file chunks")
@@ -107,6 +111,8 @@ func (wo *WebDavOption) startWebDav() bool {
 		FilerGrpcAddress: filerGrpcAddress,
 		GrpcDialOption:   grpcDialOption,
 		Collection:       *wo.collection,
+		Replication:      *wo.replication,
+		DiskType:         *wo.disk,
 		Uid:              uid,
 		Gid:              gid,
 		Cipher:           cipher,
diff --git a/weed/filer.toml b/weed/filer.toml
deleted file mode 100644
index c0530b3f1..000000000
--- a/weed/filer.toml
+++ /dev/null
@@ -1,11 +0,0 @@
-[elastic7]
-enabled = true
-servers = [
-    "http://localhost:9200",
-]
-username = ""
-password = ""
-sniff_enabled = false
-healthcheck_enabled = false
-# increase the value is recommend, be sure the value in Elastic is greater or equal here
-index.max_result_window = 10000
diff --git a/weed/filer/filer_conf.go b/weed/filer/filer_conf.go
index b4f0e5890..8e549f5ad 100644
--- a/weed/filer/filer_conf.go
+++ b/weed/filer/filer_conf.go
@@ -46,17 +46,19 @@ func (fc *FilerConf) loadFromFiler(filer *Filer) (err error) {
 		return fc.LoadFromBytes(entry.Content)
 	}
 
-	return fc.loadFromChunks(filer, entry.Chunks)
+	return fc.loadFromChunks(filer, entry.Content, entry.Chunks)
 }
 
-func (fc *FilerConf) loadFromChunks(filer *Filer, chunks []*filer_pb.FileChunk) (err error) {
-	data, err := filer.readEntry(chunks)
-	if err != nil {
-		glog.Errorf("read filer conf content: %v", err)
-		return
+func (fc *FilerConf) loadFromChunks(filer *Filer, content []byte, chunks []*filer_pb.FileChunk) (err error) {
+	if len(content) == 0 {
+		content, err = filer.readEntry(chunks)
+		if err != nil {
+			glog.Errorf("read filer conf content: %v", err)
+			return
+		}
 	}
 
-	return fc.LoadFromBytes(data)
+	return fc.LoadFromBytes(content)
 }
 
 func (fc *FilerConf) LoadFromBytes(data []byte) (err error) {
diff --git a/weed/filer/filer_on_meta_event.go b/weed/filer/filer_on_meta_event.go
index d93a7e9e3..295a5039e 100644
--- a/weed/filer/filer_on_meta_event.go
+++ b/weed/filer/filer_on_meta_event.go
@@ -40,7 +40,7 @@ func (f *Filer) readEntry(chunks []*filer_pb.FileChunk) ([]byte, error) {
 
 func (f *Filer) reloadFilerConfiguration(entry *filer_pb.Entry) {
 	fc := NewFilerConf()
-	err := fc.loadFromChunks(f, entry.Chunks)
+	err := fc.loadFromChunks(f, entry.Content, entry.Chunks)
 	if err != nil {
 		glog.Errorf("read filer conf chunks: %v", err)
 		return
diff --git a/weed/pb/grpc_client_server.go b/weed/pb/grpc_client_server.go
index ec49d177b..910114313 100644
--- a/weed/pb/grpc_client_server.go
+++ b/weed/pb/grpc_client_server.go
@@ -64,7 +64,6 @@ func GrpcDial(ctx context.Context, address string, opts ...grpc.DialOption) (*gr
 		grpc.WithDefaultCallOptions(
 			grpc.MaxCallSendMsgSize(Max_Message_Size),
 			grpc.MaxCallRecvMsgSize(Max_Message_Size),
-			grpc.WaitForReady(true),
 		),
 		grpc.WithKeepaliveParams(keepalive.ClientParameters{
 			Time:                30 * time.Second, // client ping server if no activity for this long
diff --git a/weed/server/master_grpc_server_volume.go b/weed/server/master_grpc_server_volume.go
index 1699eaa36..29aff5c0b 100644
--- a/weed/server/master_grpc_server_volume.go
+++ b/weed/server/master_grpc_server_volume.go
@@ -77,7 +77,7 @@ func (ms *MasterServer) Assign(ctx context.Context, req *master_pb.AssignRequest
 
 	if !ms.Topo.HasWritableVolume(option) {
 		if ms.Topo.AvailableSpaceFor(option) <= 0 {
-			return nil, fmt.Errorf("No free volumes left!")
+			return nil, fmt.Errorf("no free volumes left for "+option.String())
 		}
 		ms.vgLock.Lock()
 		if !ms.Topo.HasWritableVolume(option) {
diff --git a/weed/server/master_server_handlers.go b/weed/server/master_server_handlers.go
index 117423ec6..a9fecc5bd 100644
--- a/weed/server/master_server_handlers.go
+++ b/weed/server/master_server_handlers.go
@@ -113,7 +113,7 @@ func (ms *MasterServer) dirAssignHandler(w http.ResponseWriter, r *http.Request)
 
 	if !ms.Topo.HasWritableVolume(option) {
 		if ms.Topo.AvailableSpaceFor(option) <= 0 {
-			writeJsonQuiet(w, r, http.StatusNotFound, operation.AssignResult{Error: "No free volumes left!"})
+			writeJsonQuiet(w, r, http.StatusNotFound, operation.AssignResult{Error: "No free volumes left for " + option.String()})
 			return
 		}
 		ms.vgLock.Lock()
diff --git a/weed/server/webdav_server.go b/weed/server/webdav_server.go
index 4b57c7afe..c3f68fdee 100644
--- a/weed/server/webdav_server.go
+++ b/weed/server/webdav_server.go
@@ -33,6 +33,7 @@ type WebDavOption struct {
 	BucketsPath      string
 	GrpcDialOption   grpc.DialOption
 	Collection       string
+	Replication      string
 	DiskType         string
 	Uid              uint32
 	Gid              uint32
@@ -225,7 +226,7 @@ func (fs *WebDavFileSystem) OpenFile(ctx context.Context, fullFilePath string, f
 						Uid:         fs.option.Uid,
 						Gid:         fs.option.Gid,
 						Collection:  fs.option.Collection,
-						Replication: "000",
+						Replication: fs.option.Replication,
 						TtlSec:      0,
 					},
 				},
@@ -381,7 +382,7 @@ func (f *WebDavFile) saveDataAsChunk(reader io.Reader, name string, offset int64
 
 		request := &filer_pb.AssignVolumeRequest{
 			Count:       1,
-			Replication: "",
+			Replication: f.fs.option.Replication,
 			Collection:  f.fs.option.Collection,
 			DiskType:    f.fs.option.DiskType,
 			Path:        name,
diff --git a/weed/shell/command_volume_tier_move.go b/weed/shell/command_volume_tier_move.go
index 3c6c31eac..27c6815d4 100644
--- a/weed/shell/command_volume_tier_move.go
+++ b/weed/shell/command_volume_tier_move.go
@@ -20,11 +20,11 @@ type commandVolumeTierMove struct {
 }
 
 func (c *commandVolumeTierMove) Name() string {
-	return "volume.tier.upload"
+	return "volume.tier.move"
 }
 
 func (c *commandVolumeTierMove) Help() string {
-	return `change a volume from one disk type to another
+	return `<WIP> change a volume from one disk type to another
 
 	volume.tier.move -source=hdd -target=ssd [-collection=""] [-fullPercent=95] [-quietFor=1h]
 	volume.tier.move -target=hdd [-collection=""] -volumeId=<volume_id>
diff --git a/weed/shell/shell_liner.go b/weed/shell/shell_liner.go
index 2d5166acf..00adb1abc 100644
--- a/weed/shell/shell_liner.go
+++ b/weed/shell/shell_liner.go
@@ -92,7 +92,7 @@ func processEachCmd(reg *regexp.Regexp, cmd string, commandEnv *CommandEnv) bool
 
 func printGenericHelp() {
 	msg :=
-		`Type:	"help <command>" for help on <command>
+		`Type:	"help <command>" for help on <command>. Most commands support "<command> -h" also for options. 
 `
 	fmt.Print(msg)
 
diff --git a/weed/storage/super_block/replica_placement.go b/weed/storage/super_block/replica_placement.go
index fcccbba7d..65ec53819 100644
--- a/weed/storage/super_block/replica_placement.go
+++ b/weed/storage/super_block/replica_placement.go
@@ -6,9 +6,9 @@ import (
 )
 
 type ReplicaPlacement struct {
-	SameRackCount       int
-	DiffRackCount       int
-	DiffDataCenterCount int
+	SameRackCount       int `json:"node,omitempty"`
+	DiffRackCount       int `json:"rack,omitempty"`
+	DiffDataCenterCount int `json:"dc,omitempty"`
 }
 
 func NewReplicaPlacementFromString(t string) (*ReplicaPlacement, error) {
diff --git a/weed/topology/data_node.go b/weed/topology/data_node.go
index 1a0ebf761..69f739dd5 100644
--- a/weed/topology/data_node.go
+++ b/weed/topology/data_node.go
@@ -207,7 +207,26 @@ func (dn *DataNode) ToMap() interface{} {
 	ret := make(map[string]interface{})
 	ret["Url"] = dn.Url()
 	ret["PublicUrl"] = dn.PublicUrl
-	ret["Disks"] = dn.diskUsages.ToMap()
+
+	// aggregated volume info
+	var volumeCount, ecShardCount, maxVolumeCount int64
+	var volumeIds string
+	for _, diskUsage := range dn.diskUsages.usages {
+		volumeCount += diskUsage.volumeCount
+		ecShardCount += diskUsage.ecShardCount
+		maxVolumeCount += diskUsage.maxVolumeCount
+	}
+
+	for _, disk := range dn.Children() {
+		d := disk.(*Disk)
+		volumeIds += " " + d.GetVolumeIds()
+	}
+
+	ret["Volumes"] = volumeCount
+	ret["EcShards"] = ecShardCount
+	ret["Max"] = maxVolumeCount
+	ret["VolumeIds"] = volumeIds
+
 	return ret
 }
 
diff --git a/weed/topology/disk.go b/weed/topology/disk.go
index 37d5e1272..a085f8dff 100644
--- a/weed/topology/disk.go
+++ b/weed/topology/disk.go
@@ -58,16 +58,6 @@ func (d *DiskUsages) negative() *DiskUsages {
 	return t
 }
 
-func (d *DiskUsages) ToMap() interface{} {
-	d.RLock()
-	defer d.RUnlock()
-	ret := make(map[string]interface{})
-	for diskType, diskUsage := range d.usages {
-		ret[diskType.String()] = diskUsage.ToMap()
-	}
-	return ret
-}
-
 func (d *DiskUsages) ToDiskInfo() map[string]*master_pb.DiskInfo {
 	ret := make(map[string]*master_pb.DiskInfo)
 	for diskType, diskUsageCounts := range d.usages {
@@ -135,15 +125,6 @@ func (a *DiskUsageCounts) minus(b *DiskUsageCounts) *DiskUsageCounts {
 	}
 }
 
-func (diskUsage *DiskUsageCounts) ToMap() interface{} {
-	ret := make(map[string]interface{})
-	ret["Volumes"] = diskUsage.volumeCount
-	ret["EcShards"] = diskUsage.ecShardCount
-	ret["Max"] = diskUsage.maxVolumeCount
-	ret["Free"] = diskUsage.FreeSpace()
-	return ret
-}
-
 func (du *DiskUsages) getOrCreateDisk(diskType types.DiskType) *DiskUsageCounts {
 	du.Lock()
 	defer du.Unlock()
diff --git a/weed/topology/volume_growth.go b/weed/topology/volume_growth.go
index 4b0a4837e..8941a049b 100644
--- a/weed/topology/volume_growth.go
+++ b/weed/topology/volume_growth.go
@@ -1,6 +1,7 @@
 package topology
 
 import (
+	"encoding/json"
 	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/storage/types"
 	"math/rand"
@@ -25,15 +26,15 @@ This package is created to resolve these replica placement issues:
 */
 
 type VolumeGrowOption struct {
-	Collection         string
-	ReplicaPlacement   *super_block.ReplicaPlacement
-	Ttl                *needle.TTL
-	DiskType           types.DiskType
-	Prealloacte        int64
-	DataCenter         string
-	Rack               string
-	DataNode           string
-	MemoryMapMaxSizeMb uint32
+	Collection         string                        `json:"collection,omitempty"`
+	ReplicaPlacement   *super_block.ReplicaPlacement `json:"replication,omitempty"`
+	Ttl                *needle.TTL                   `json:"ttl,omitempty"`
+	DiskType           types.DiskType                `json:"disk,omitempty"`
+	Prealloacte        int64                         `json:"prealloacte,omitempty"`
+	DataCenter         string                        `json:"dataCenter,omitempty"`
+	Rack               string                        `json:"rack,omitempty"`
+	DataNode           string                        `json:"dataNode,omitempty"`
+	MemoryMapMaxSizeMb uint32                        `json:"memoryMapMaxSizeMb,omitempty"`
 }
 
 type VolumeGrowth struct {
@@ -41,7 +42,8 @@ type VolumeGrowth struct {
 }
 
 func (o *VolumeGrowOption) String() string {
-	return fmt.Sprintf("Collection:%s, ReplicaPlacement:%v, Ttl:%v, DataCenter:%s, Rack:%s, DataNode:%s", o.Collection, o.ReplicaPlacement, o.Ttl, o.DataCenter, o.Rack, o.DataNode)
+	blob, _ := json.Marshal(o)
+	return string(blob)
 }
 
 func NewDefaultVolumeGrowth() *VolumeGrowth {