diff --git a/weed/Makefile b/weed/Makefile
index f537fe051..0e2d29623 100644
--- a/weed/Makefile
+++ b/weed/Makefile
@@ -16,7 +16,7 @@ debug_shell:
 
 debug_mount:
 	go build -gcflags="all=-N -l"
-	dlv --listen=:2345 --headless=true --api-version=2 --accept-multiclient exec weed -- mount -dir=~/tmp/mm
+	dlv --listen=:2345 --headless=true --api-version=2 --accept-multiclient exec weed -- mount -dir=~/tmp/mm -cacheCapacityMB=0 -filer.path=/buckets
 
 debug_server:
 	go build -gcflags="all=-N -l"
diff --git a/weed/filesys/meta_cache/meta_cache.go b/weed/filesys/meta_cache/meta_cache.go
index bb81d6d27..247f0ce81 100644
--- a/weed/filesys/meta_cache/meta_cache.go
+++ b/weed/filesys/meta_cache/meta_cache.go
@@ -22,10 +22,10 @@ type MetaCache struct {
 	uidGidMapper    *UidGidMapper
 }
 
-func NewMetaCache(dbFolder string, uidGidMapper *UidGidMapper) *MetaCache {
+func NewMetaCache(dbFolder string, baseDir util.FullPath, uidGidMapper *UidGidMapper) *MetaCache {
 	return &MetaCache{
 		localStore:      openMetaStore(dbFolder),
-		visitedBoundary: bounded_tree.NewBoundedTree(),
+		visitedBoundary: bounded_tree.NewBoundedTree(baseDir),
 		uidGidMapper:    uidGidMapper,
 	}
 }
diff --git a/weed/filesys/wfs.go b/weed/filesys/wfs.go
index 57b4c3da5..265fc95a8 100644
--- a/weed/filesys/wfs.go
+++ b/weed/filesys/wfs.go
@@ -92,7 +92,7 @@ func NewSeaweedFileSystem(option *Option) *WFS {
 		wfs.chunkCache = chunk_cache.NewTieredChunkCache(256, cacheDir, option.CacheSizeMB, 1024*1024)
 	}
 
-	wfs.metaCache = meta_cache.NewMetaCache(path.Join(cacheDir, "meta"), option.UidGidMapper)
+	wfs.metaCache = meta_cache.NewMetaCache(path.Join(cacheDir, "meta"), util.FullPath(option.FilerMountRootPath), option.UidGidMapper)
 	startTime := time.Now()
 	go meta_cache.SubscribeMetaEvents(wfs.metaCache, wfs.signature, wfs, wfs.option.FilerMountRootPath, startTime.UnixNano())
 	grace.OnInterrupt(func() {
diff --git a/weed/util/bounded_tree/bounded_tree.go b/weed/util/bounded_tree/bounded_tree.go
index 0e023c0d1..0182aeba1 100644
--- a/weed/util/bounded_tree/bounded_tree.go
+++ b/weed/util/bounded_tree/bounded_tree.go
@@ -16,13 +16,15 @@ type Node struct {
 type BoundedTree struct {
 	root *Node
 	sync.RWMutex
+	baseDir util.FullPath
 }
 
-func NewBoundedTree() *BoundedTree {
+func NewBoundedTree(baseDir util.FullPath) *BoundedTree {
 	return &BoundedTree{
 		root: &Node{
 			Name: "/",
 		},
+		baseDir: baseDir,
 	}
 }
 
@@ -39,9 +41,12 @@ func (t *BoundedTree) EnsureVisited(p util.FullPath, visitFn VisitNodeFunc) {
 	if t.root == nil {
 		return
 	}
+	if t.baseDir != "/" {
+		p = p[len(t.baseDir):]
+	}
 	components := p.Split()
 	// fmt.Printf("components %v %d\n", components, len(components))
-	if canDelete := t.ensureVisited(t.root, util.FullPath("/"), components, 0, visitFn); canDelete {
+	if canDelete := t.ensureVisited(t.root, t.baseDir, components, 0, visitFn); canDelete {
 		t.root = nil
 	}
 }
@@ -60,7 +65,12 @@ func (t *BoundedTree) ensureVisited(n *Node, currentPath util.FullPath, componen
 	} else {
 		// fmt.Printf("ensure %v\n", currentPath)
 
-		children, err := visitFn(currentPath)
+		filerPath := currentPath
+		if t.baseDir != "/" {
+			filerPath = t.baseDir + filerPath
+		}
+
+		children, err := visitFn(filerPath)
 		if err != nil {
 			glog.V(0).Infof("failed to visit %s: %v", currentPath, err)
 			return
diff --git a/weed/util/bounded_tree/bounded_tree_test.go b/weed/util/bounded_tree/bounded_tree_test.go
index 0b9c3177a..465f1cc9c 100644
--- a/weed/util/bounded_tree/bounded_tree_test.go
+++ b/weed/util/bounded_tree/bounded_tree_test.go
@@ -52,7 +52,7 @@ func TestBoundedTree(t *testing.T) {
 	// g
 	// h
 
-	tree := NewBoundedTree()
+	tree := NewBoundedTree(util.FullPath("/"))
 
 	tree.EnsureVisited(util.FullPath("/a/b/c"), visitFn)
 
@@ -100,7 +100,7 @@ func TestEmptyBoundedTree(t *testing.T) {
 	// g
 	// h
 
-	tree := NewBoundedTree()
+	tree := NewBoundedTree(util.FullPath("/"))
 
 	visitFn := func(path util.FullPath) (childDirectories []string, err error) {
 		fmt.Printf("  visit %v ...\n", path)