diff --git a/go/weed/master.go b/go/weed/master.go
index 6d01ef3bc..2d7adef1f 100644
--- a/go/weed/master.go
+++ b/go/weed/master.go
@@ -10,6 +10,7 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
+	"os"
 	"runtime"
 	"strconv"
 	"strings"
@@ -32,7 +33,7 @@ var cmdMaster = &Command{
 
 var (
 	mport                 = cmdMaster.Flag.Int("port", 9333, "http listen port")
-	metaFolder            = cmdMaster.Flag.String("mdir", "/tmp", "data directory to store mappings")
+	metaFolder            = cmdMaster.Flag.String("mdir", os.TempDir(), "data directory to store mappings")
 	volumeSizeLimitMB     = cmdMaster.Flag.Uint("volumeSizeLimitMB", 32*1024, "Default Volume Size in MegaBytes")
 	mpulse                = cmdMaster.Flag.Int("pulseSeconds", 5, "number of seconds between heartbeats")
 	confFile              = cmdMaster.Flag.String("conf", "/etc/weedfs/weedfs.conf", "xml configuration file")
diff --git a/go/weed/volume.go b/go/weed/volume.go
index 34c2bc30b..3c4db7ff1 100644
--- a/go/weed/volume.go
+++ b/go/weed/volume.go
@@ -31,7 +31,7 @@ var cmdVolume = &Command{
 
 var (
 	vport                 = cmdVolume.Flag.Int("port", 8080, "http listen port")
-	volumeFolders         = cmdVolume.Flag.String("dir", "/tmp", "directories to store data files. dir[,dir]...")
+	volumeFolders         = cmdVolume.Flag.String("dir", os.TempDir(), "directories to store data files. dir[,dir]...")
 	maxVolumeCounts       = cmdVolume.Flag.String("max", "7", "maximum numbers of volumes, count[,count]...")
 	ip                    = cmdVolume.Flag.String("ip", "localhost", "ip or server name")
 	publicUrl             = cmdVolume.Flag.String("publicUrl", "", "Publicly accessible <ip|server_name>:<port>")