diff --git a/Customize-Filer-Store.md b/Customize-Filer-Store.md
index 8be3db8..f7937f5 100644
--- a/Customize-Filer-Store.md
+++ b/Customize-Filer-Store.md
@@ -3,10 +3,10 @@ It is fairly easy if you need to store filer metadata with other data store.
 Let's use "yourstore" as the chosen name.
 
 Here are the steps:
-1. Add a package under github.com/chrislusf/seaweedfs/weed/filer2/yourstore
-2. Implement the filer2.FilerStore interface
+1. Add a package under github.com/chrislusf/seaweedfs/weed/filer/yourstore
+2. Implement the filer.FilerStore interface
 ```
-package filer2
+package filer
 
 import (
 	"errors"
@@ -16,12 +16,25 @@ type FilerStore interface {
 	// GetName gets the name to locate the configuration in filer.toml file
 	GetName() string
 	// Initialize initializes the file store
-	Initialize(configuration Configuration) error
-	InsertEntry(*Entry) error
-	UpdateEntry(*Entry) (err error)
-	FindEntry(FullPath) (entry *Entry, err error)
-	DeleteEntry(FullPath) (err error)
-	ListDirectoryEntries(dirPath FullPath, startFileName string, includeStartFile bool, limit int) ([]*Entry, error)
+	Initialize(configuration util.Configuration, prefix string) error
+	InsertEntry(context.Context, *Entry) error
+	UpdateEntry(context.Context, *Entry) (err error)
+	// err == filer2.ErrNotFound if not found
+	FindEntry(context.Context, util.FullPath) (entry *Entry, err error)
+	DeleteEntry(context.Context, util.FullPath) (err error)
+	DeleteFolderChildren(context.Context, util.FullPath) (err error)
+	ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int) ([]*Entry, error)
+	ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int, prefix string) ([]*Entry, error)
+
+	BeginTransaction(ctx context.Context) (context.Context, error)
+	CommitTransaction(ctx context.Context) error
+	RollbackTransaction(ctx context.Context) error
+
+	KvPut(ctx context.Context, key []byte, value []byte) (err error)
+	KvGet(ctx context.Context, key []byte) (value []byte, err error)
+	KvDelete(ctx context.Context, key []byte) (err error)
+
+	Shutdown()
 }
 
 ```
@@ -37,13 +50,13 @@ func init() {
 import (
 	"net/http"
 	"strconv"
-	"github.com/chrislusf/seaweedfs/weed/filer2"
-	_ "github.com/chrislusf/seaweedfs/weed/filer2/cassandra"
-	_ "github.com/chrislusf/seaweedfs/weed/filer2/leveldb"
-	_ "github.com/chrislusf/seaweedfs/weed/filer2/mysql"
-	_ "github.com/chrislusf/seaweedfs/weed/filer2/postgres"
-	_ "github.com/chrislusf/seaweedfs/weed/filer2/redis"
-	_ "github.com/chrislusf/seaweedfs/weed/filer2/yourstore"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	_ "github.com/chrislusf/seaweedfs/weed/filer/cassandra"
+	_ "github.com/chrislusf/seaweedfs/weed/filer/leveldb"
+	_ "github.com/chrislusf/seaweedfs/weed/filer/mysql"
+	_ "github.com/chrislusf/seaweedfs/weed/filer/postgres"
+	_ "github.com/chrislusf/seaweedfs/weed/filer/redis"
+	_ "github.com/chrislusf/seaweedfs/weed/filer/yourstore"
         // ^^ add here
 	"github.com/chrislusf/seaweedfs/weed/security"
 	"github.com/chrislusf/seaweedfs/weed/glog"