Add InMemory to Volume Grow structure

weed/topology/allocate_volume.go

@@ -23,6 +23,7 @@ func AllocateVolume(dn *DataNode, grpcDialOption grpc.DialOption, vid needle.Vol
 			Replication: option.ReplicaPlacement.String(),
 			Ttl:         option.Ttl.String(),
 			Preallocate: option.Prealloacte,
+			InMemory:    option.InMemory,
 		})
 		return deleteErr
 	})

weed/topology/volume_growth.go

@@ -28,6 +28,7 @@ type VolumeGrowOption struct {
 	DataCenter       string
 	Rack             string
 	DataNode         string
+	InMemory         bool
 }
 
 type VolumeGrowth struct {