Major:

change replication_type to ReplicaPlacement, hopefully cleaner code
works for 9 possible ReplicaPlacement
xyz
x : number of copies on other data centers
y : number of copies on other racks
z : number of copies on current rack
x y z each can be 0,1,2

Minor:
weed server "-mdir" default to "-dir" if empty

go/storage/compact_map_perf_test.go

@@ -3,8 +3,8 @@ package storage
 import (
 	"code.google.com/p/weed-fs/go/glog"
 	"code.google.com/p/weed-fs/go/util"
-	"os"
 	"log"
+	"os"
 	"testing"
 )