just exit in case of duplicated volume directories were loaded

weed/server/volume_server.go

@@ -2,7 +2,6 @@ package weed_server
 
 import (
 	"net/http"
-	"os"
 	"sync"
 
 	"github.com/chrislusf/seaweedfs/weed/pb"
@@ -45,7 +44,6 @@ type VolumeServer struct {
 	fileSizeLimitBytes      int64
 	isHeartbeating          bool
 	stopChan                chan bool
-	pid                     int
 }
 
 func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
@@ -89,7 +87,6 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 		inFlightDownloadDataLimitCond: sync.NewCond(new(sync.Mutex)),
 		concurrentUploadLimit:         concurrentUploadLimit,
 		concurrentDownloadLimit:       concurrentDownloadLimit,
-		pid:                           os.Getpid(),
 	}
 	vs.SeedMasterNodes = masterNodes