diff --git a/weed/command/server.go b/weed/command/server.go
index 4a9c2411a..0c6731eb2 100644
--- a/weed/command/server.go
+++ b/weed/command/server.go
@@ -105,6 +105,7 @@ func init() {
 	serverOptions.v.publicUrl = cmdServer.Flag.String("volume.publicUrl", "", "publicly accessible address")
 	serverOptions.v.preStopSeconds = cmdServer.Flag.Int("volume.preStopSeconds", 10, "number of seconds between stop send heartbeats and stop volume server")
 	serverOptions.v.pprof = cmdServer.Flag.Bool("volume.pprof", false, "enable pprof http handlers. precludes --memprofile and --cpuprofile")
+	serverOptions.v.idxFolder = cmdServer.Flag.String("volume.dir.idx", "", "directory to store .idx files")
 
 	s3Options.port = cmdServer.Flag.Int("s3.port", 8333, "s3 server http listen port")
 	s3Options.domainName = cmdServer.Flag.String("s3.domainName", "", "suffix of the host name in comma separated list, {bucket}.{domainName}")
diff --git a/weed/command/volume.go b/weed/command/volume.go
index ce5992665..9597e843a 100644
--- a/weed/command/volume.go
+++ b/weed/command/volume.go
@@ -39,6 +39,7 @@ type VolumeServerOptions struct {
 	publicPort            *int
 	folders               []string
 	folderMaxLimits       []int
+	idxFolder             *string
 	ip                    *string
 	publicUrl             *string
 	bindIp                *string
@@ -83,6 +84,7 @@ func init() {
 	v.fileSizeLimitMB = cmdVolume.Flag.Int("fileSizeLimitMB", 256, "limit file size to avoid out of memory")
 	v.pprof = cmdVolume.Flag.Bool("pprof", false, "enable pprof http handlers. precludes --memprofile and --cpuprofile")
 	v.metricsHttpPort = cmdVolume.Flag.Int("metricsPort", 0, "Prometheus metrics listen port")
+	v.idxFolder = cmdVolume.Flag.String("dir.idx", "", "directory to store .idx files")
 }
 
 var cmdVolume = &Command{
@@ -211,6 +213,7 @@ func (v VolumeServerOptions) startVolumeServer(volumeFolders, maxVolumeCounts, v
 	volumeServer := weed_server.NewVolumeServer(volumeMux, publicVolumeMux,
 		*v.ip, *v.port, *v.publicUrl,
 		v.folders, v.folderMaxLimits, v.minFreeSpacePercents,
+		*v.idxFolder,
 		volumeNeedleMapKind,
 		strings.Split(masters, ","), 5, *v.dataCenter, *v.rack,
 		v.whiteList,
diff --git a/weed/server/volume_server.go b/weed/server/volume_server.go
index 83df32fdd..468f75890 100644
--- a/weed/server/volume_server.go
+++ b/weed/server/volume_server.go
@@ -38,6 +38,7 @@ type VolumeServer struct {
 func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 	port int, publicUrl string,
 	folders []string, maxCounts []int, minFreeSpacePercents []float32,
+	idxFolder string,
 	needleMapKind storage.NeedleMapType,
 	masterNodes []string, pulseSeconds int,
 	dataCenter string, rack string,
@@ -75,7 +76,7 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 
 	vs.checkWithMaster()
 
-	vs.store = storage.NewStore(vs.grpcDialOption, port, ip, publicUrl, folders, maxCounts, minFreeSpacePercents, vs.needleMapKind)
+	vs.store = storage.NewStore(vs.grpcDialOption, port, ip, publicUrl, folders, maxCounts, minFreeSpacePercents, idxFolder, vs.needleMapKind)
 	vs.guard = security.NewGuard(whiteList, signingKey, expiresAfterSec, readSigningKey, readExpiresAfterSec)
 
 	handleStaticResources(adminMux)
diff --git a/weed/storage/disk_location.go b/weed/storage/disk_location.go
index 775ebf092..f2b0d7e9f 100644
--- a/weed/storage/disk_location.go
+++ b/weed/storage/disk_location.go
@@ -18,6 +18,7 @@ import (
 
 type DiskLocation struct {
 	Directory              string
+	IdxDirectory           string
 	MaxVolumeCount         int
 	OriginalMaxVolumeCount int
 	MinFreeSpacePercent    float32
@@ -31,8 +32,20 @@ type DiskLocation struct {
 	isDiskSpaceLow bool
 }
 
-func NewDiskLocation(dir string, maxVolumeCount int, minFreeSpacePercent float32) *DiskLocation {
-	location := &DiskLocation{Directory: dir, MaxVolumeCount: maxVolumeCount, OriginalMaxVolumeCount: maxVolumeCount, MinFreeSpacePercent: minFreeSpacePercent}
+func NewDiskLocation(dir string, maxVolumeCount int, minFreeSpacePercent float32, idxDir string) *DiskLocation {
+	dir = util.ResolvePath(dir)
+	if idxDir == "" {
+		idxDir = dir
+	} else {
+		idxDir = util.ResolvePath(idxDir)
+	}
+	location := &DiskLocation{
+		Directory: dir,
+		IdxDirectory: idxDir,
+		MaxVolumeCount: maxVolumeCount,
+		OriginalMaxVolumeCount: maxVolumeCount,
+		MinFreeSpacePercent: minFreeSpacePercent,
+	}
 	location.volumes = make(map[needle.VolumeId]*Volume)
 	location.ecVolumes = make(map[needle.VolumeId]*erasure_coding.EcVolume)
 	go location.CheckDiskSpace()
diff --git a/weed/storage/store.go b/weed/storage/store.go
index 7f2415448..ce4e500d6 100644
--- a/weed/storage/store.go
+++ b/weed/storage/store.go
@@ -16,7 +16,6 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/storage/needle"
 	"github.com/chrislusf/seaweedfs/weed/storage/super_block"
 	. "github.com/chrislusf/seaweedfs/weed/storage/types"
-	"github.com/chrislusf/seaweedfs/weed/util"
 )
 
 const (
@@ -53,11 +52,11 @@ func (s *Store) String() (str string) {
 	return
 }
 
-func NewStore(grpcDialOption grpc.DialOption, port int, ip, publicUrl string, dirnames []string, maxVolumeCounts []int, minFreeSpacePercents []float32, needleMapKind NeedleMapType) (s *Store) {
+func NewStore(grpcDialOption grpc.DialOption, port int, ip, publicUrl string, dirnames []string, maxVolumeCounts []int, minFreeSpacePercents []float32, idxFolder string, needleMapKind NeedleMapType) (s *Store) {
 	s = &Store{grpcDialOption: grpcDialOption, Port: port, Ip: ip, PublicUrl: publicUrl, NeedleMapType: needleMapKind}
 	s.Locations = make([]*DiskLocation, 0)
 	for i := 0; i < len(dirnames); i++ {
-		location := NewDiskLocation(util.ResolvePath(dirnames[i]), maxVolumeCounts[i], minFreeSpacePercents[i])
+		location := NewDiskLocation(dirnames[i], maxVolumeCounts[i], minFreeSpacePercents[i], idxFolder)
 		location.loadExistingVolumes(needleMapKind)
 		s.Locations = append(s.Locations, location)
 		stats.VolumeServerMaxVolumeCounter.Add(float64(maxVolumeCounts[i]))