diff --git a/container_test.go b/container_test.go
index 6eedc6c658..161b32d76b 100644
--- a/container_test.go
+++ b/container_test.go
@@ -1,7 +1,9 @@
 package docker
 
 import (
+	"fmt"
 	"testing"
+	"time"
 )
 
 func TestStart(t *testing.T) {
@@ -240,3 +242,87 @@ func TestMultipleContainers(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func BenchmarkRunSequencial(b *testing.B) {
+	docker, err := newTestDocker()
+	if err != nil {
+		b.Fatal(err)
+	}
+	for i := 0; i < b.N; i++ {
+		container, err := docker.Create(
+			fmt.Sprintf("bench_%v", i),
+			"echo",
+			[]string{"-n", "foo"},
+			[]string{"/var/lib/docker/images/ubuntu"},
+			&Config{},
+		)
+		if err != nil {
+			b.Fatal(err)
+		}
+		defer docker.Destroy(container)
+		output, err := container.Output()
+		if err != nil {
+			b.Fatal(err)
+		}
+		if string(output) != "foo" {
+			b.Fatalf("Unexecpted output: %v", string(output))
+		}
+		if err := docker.Destroy(container); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkRunParallel(b *testing.B) {
+	docker, err := newTestDocker()
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	var tasks []chan error
+
+	for i := 0; i < b.N; i++ {
+		complete := make(chan error)
+		tasks = append(tasks, complete)
+		go func(i int, complete chan error) {
+			container, err := docker.Create(
+				fmt.Sprintf("bench_%v", i),
+				"echo",
+				[]string{"-n", "foo"},
+				[]string{"/var/lib/docker/images/ubuntu"},
+				&Config{},
+			)
+			if err != nil {
+				complete <- err
+				return
+			}
+			defer docker.Destroy(container)
+			if err := container.Start(); err != nil {
+				complete <- err
+				return
+			}
+			if err := container.WaitTimeout(15 * time.Second); err != nil {
+				complete <- err
+				return
+			}
+			// if string(output) != "foo" {
+			// 	complete <- fmt.Errorf("Unexecpted output: %v", string(output))
+			// }
+			if err := docker.Destroy(container); err != nil {
+				complete <- err
+				return
+			}
+			complete <- nil
+		}(i, complete)
+	}
+	var errors []error
+	for _, task := range tasks {
+		err := <-task
+		if err != nil {
+			errors = append(errors, err)
+		}
+	}
+	if len(errors) > 0 {
+		b.Fatal(errors)
+	}
+}
diff --git a/docker.go b/docker.go
index 8a79e989a9..7f9442306a 100644
--- a/docker.go
+++ b/docker.go
@@ -67,10 +67,14 @@ func (docker *Docker) Destroy(container *Container) error {
 	if err := container.Stop(); err != nil {
 		return err
 	}
-	if err := os.RemoveAll(container.Root); err != nil {
-		return err
+	if container.Filesystem.IsMounted() {
+		if err := container.Filesystem.Umount(); err != nil {
+			log.Printf("Unable to umount container %v: %v", container.Id, err)
+		}
+	}
+	if err := os.RemoveAll(container.Root); err != nil {
+		log.Printf("Unable to remove filesystem for %v: %v", container.Id, err)
 	}
-
 	docker.containers.Remove(element)
 	return nil
 }
diff --git a/filesystem.go b/filesystem.go
index 543770dc6b..030625a150 100644
--- a/filesystem.go
+++ b/filesystem.go
@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"strings"
 	"syscall"
+	"time"
 	"io"
 	"io/ioutil"
 )
@@ -40,33 +41,59 @@ func (fs *Filesystem) Mount() error {
 		roBranches += fmt.Sprintf("%v=ro:", layer)
 	}
 	branches := fmt.Sprintf("br:%v:%v", rwBranch, roBranches)
-	return syscall.Mount("none", fs.RootFS, "aufs", 0, branches)
+	if err := syscall.Mount("none", fs.RootFS, "aufs", 0, branches); err != nil {
+		return err
+	}
+	if !fs.IsMounted() {
+		return errors.New("Mount failed")
+	}
+	return nil
 }
 
 func (fs *Filesystem) Umount() error {
 	if !fs.IsMounted() {
 		return errors.New("Umount: Filesystem not mounted")
 	}
-	return syscall.Unmount(fs.RootFS, 0)
+	if err := syscall.Unmount(fs.RootFS, 0); err != nil {
+		return err
+	}
+	if fs.IsMounted() {
+		return fmt.Errorf("Umount: Filesystem still mounted after calling umount(%v)", fs.RootFS)
+	}
+	// Even though we just unmounted the filesystem, AUFS will prevent deleting the mntpoint
+	// for some time. We'll just keep retrying until it succeeds.
+	for retries := 0; retries < 1000; retries++ {
+		err := os.Remove(fs.RootFS)
+		if err == nil {
+			// rm mntpoint succeeded
+			return nil
+		}
+		if os.IsNotExist(err) {
+			// mntpoint doesn't exist anymore. Success.
+			return nil
+		}
+		// fmt.Printf("(%v) Remove %v returned: %v\n", retries, fs.RootFS, err)
+		time.Sleep(10 * time.Millisecond)
+	}
+	return fmt.Errorf("Umount: Failed to umount %v", fs.RootFS)
 }
 
 func (fs *Filesystem) IsMounted() bool {
-	f, err := os.Open(fs.RootFS)
+	mntpoint, err := os.Stat(fs.RootFS)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return false
 		}
 		panic(err)
 	}
-	list, err := f.Readdirnames(1)
-	f.Close()
+	parent, err := os.Stat(filepath.Join(fs.RootFS, ".."))
 	if err != nil {
-		return false
+		panic(err)
 	}
-	if len(list) > 0 {
-		return true
-	}
-	return false
+
+	mntpointSt := mntpoint.Sys().(*syscall.Stat_t)
+	parentSt := parent.Sys().(*syscall.Stat_t)
+	return mntpointSt.Dev != parentSt.Dev
 }
 
 // Tar returns the contents of the filesystem as an uncompressed tar stream
diff --git a/filesystem_test.go b/filesystem_test.go
index b4deb02b36..fb57344ede 100644
--- a/filesystem_test.go
+++ b/filesystem_test.go
@@ -27,21 +27,41 @@ func TestFilesystem(t *testing.T) {
 		t.Errorf("Umount succeeded even though the filesystem was not mounted")
 	}
 
+	if filesystem.IsMounted() {
+		t.Fatal("Filesystem should not be mounted")
+	}
+
 	if err := filesystem.Mount(); err != nil {
 		t.Fatal(err)
 	}
 
+	if !filesystem.IsMounted() {
+		t.Fatal("Filesystem should be mounted")
+	}
+
 	if err := filesystem.Mount(); err == nil {
 		t.Errorf("Double mount succeeded")
 	}
 
+	if !filesystem.IsMounted() {
+		t.Fatal("Filesystem should be mounted")
+	}
+
 	if err := filesystem.Umount(); err != nil {
 		t.Fatal(err)
 	}
 
+	if filesystem.IsMounted() {
+		t.Fatal("Filesystem should not be mounted")
+	}
+
 	if err := filesystem.Umount(); err == nil {
 		t.Errorf("Umount succeeded even though the filesystem was already umounted")
 	}
+
+	if filesystem.IsMounted() {
+		t.Fatal("Filesystem should not be mounted")
+	}
 }
 
 func TestFilesystemMultiLayer(t *testing.T) {