diff --git a/snapshot/btrfs.go b/snapshot/btrfs/btrfs.go
similarity index 93%
rename from snapshot/btrfs.go
rename to snapshot/btrfs/btrfs.go
index 32a40ff..f5ebd0e 100644
--- a/snapshot/btrfs.go
+++ b/snapshot/btrfs/btrfs.go
@@ -1,6 +1,7 @@
-package snapshot
+package btrfs
 
 import (
+	"crypto/sha256"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -26,7 +27,6 @@ func (lm *Btrfs) Prepare(key, parent string) ([]containerd.Mount, error) {
 
 	dir := filepath.Join(active, hash(key))
 
-	fmt.Println("dir", dir)
 	if parent == "" {
 		// create new subvolume
 		// btrfs subvolume create /dir
@@ -69,3 +69,7 @@ func (lm *Btrfs) Commit(name, key string) error {
 
 	return btrfs.SubvolDelete(dir)
 }
+
+func hash(k string) string {
+	return fmt.Sprintf("%x", sha256.Sum224([]byte(k)))
+}
diff --git a/snapshot/btrfs_test.go b/snapshot/btrfs/btrfs_test.go
similarity index 96%
rename from snapshot/btrfs_test.go
rename to snapshot/btrfs/btrfs_test.go
index 7fa3a68..5678bce 100644
--- a/snapshot/btrfs_test.go
+++ b/snapshot/btrfs/btrfs_test.go
@@ -1,4 +1,4 @@
-package snapshot
+package btrfs
 
 import (
 	"bytes"
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"github.com/docker/containerd"
+	"github.com/docker/containerd/snapshot/testutil"
 	btrfs "github.com/stevvooe/go-btrfs"
 )
 
@@ -53,7 +54,7 @@ func TestBtrfs(t *testing.T) {
 	if err := containerd.MountAll(mounts...); err != nil {
 		t.Fatal(err)
 	}
-	defer unmountAll(t, mounts)
+	defer testutil.UnmountAll(t, mounts)
 
 	// write in some data
 	if err := ioutil.WriteFile(filepath.Join(mounts[0].Target, "foo"), []byte("content"), 0777); err != nil {
@@ -89,7 +90,7 @@ func TestBtrfs(t *testing.T) {
 	if err := containerd.MountAll(mounts...); err != nil {
 		t.Fatal(err)
 	}
-	defer unmountAll(t, mounts)
+	defer testutil.UnmountAll(t, mounts)
 
 	// TODO(stevvooe): Verify contents of "foo"
 	if err := ioutil.WriteFile(filepath.Join(mounts[0].Target, "bar"), []byte("content"), 0777); err != nil {
@@ -182,7 +183,7 @@ func setupBtrfsLoopbackDevice(t *testing.T) *testDevice {
 // file holding the disk image.
 func removeBtrfsLoopbackDevice(t *testing.T, device *testDevice) {
 	// unmount
-	unmount(t, device.mountPoint)
+	testutil.Unmount(t, device.mountPoint)
 
 	// detach device
 	t.Log("Removing loop device")
diff --git a/snapshot/manager_test.go b/snapshot/manager_test.go
index 992b65e..5b21434 100644
--- a/snapshot/manager_test.go
+++ b/snapshot/manager_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/docker/containerd"
+	"github.com/docker/containerd/snapshot/testutil"
 )
 
 // TestSnapshotManagerBasic implements something similar to the conceptual
@@ -58,7 +59,7 @@ func TestSnapshotManagerBasic(t *testing.T) {
 	if err := containerd.MountAll(mounts...); err != nil {
 		t.Fatal(err)
 	}
-	defer unmountAll(t, mounts)
+	defer testutil.UnmountAll(t, mounts)
 
 	if err := ioutil.WriteFile(filepath.Join(preparing, "foo"), []byte("foo\n"), 0777); err != nil {
 		t.Fatal(err)
@@ -88,7 +89,7 @@ func TestSnapshotManagerBasic(t *testing.T) {
 	if err := containerd.MountAll(mounts...); err != nil {
 		t.Fatal(err)
 	}
-	defer unmountAll(t, mounts)
+	defer testutil.UnmountAll(t, mounts)
 
 	for _, mount := range mounts {
 		if !strings.HasPrefix(mount.Target, next) {
diff --git a/snapshot/naive.go b/snapshot/naive/naive.go
similarity index 99%
rename from snapshot/naive.go
rename to snapshot/naive/naive.go
index 449afd8..5f50162 100644
--- a/snapshot/naive.go
+++ b/snapshot/naive/naive.go
@@ -1,4 +1,4 @@
-package snapshot
+package naive
 
 import (
 	"fmt"
diff --git a/snapshot/naive_test.go b/snapshot/naive/naive_test.go
similarity index 99%
rename from snapshot/naive_test.go
rename to snapshot/naive/naive_test.go
index 8ab5f88..0d72997 100644
--- a/snapshot/naive_test.go
+++ b/snapshot/naive/naive_test.go
@@ -1,4 +1,4 @@
-package snapshot
+package naive
 
 import (
 	"io/ioutil"
diff --git a/snapshot/overlayfs.go b/snapshot/overlay/overlayfs.go
similarity index 99%
rename from snapshot/overlayfs.go
rename to snapshot/overlay/overlayfs.go
index e82b573..a3f5f0e 100644
--- a/snapshot/overlayfs.go
+++ b/snapshot/overlay/overlayfs.go
@@ -1,4 +1,4 @@
-package snapshot
+package overlay
 
 import (
 	"crypto/md5"
diff --git a/snapshot/overlayfs_test.go b/snapshot/overlay/overlayfs_test.go
similarity index 99%
rename from snapshot/overlayfs_test.go
rename to snapshot/overlay/overlayfs_test.go
index ebc4aa4..0b67131 100644
--- a/snapshot/overlayfs_test.go
+++ b/snapshot/overlay/overlayfs_test.go
@@ -1,4 +1,4 @@
-package snapshot
+package overlay
 
 import (
 	"io/ioutil"
diff --git a/snapshot/common_test.go b/snapshot/testutil/helpers.go
similarity index 64%
rename from snapshot/common_test.go
rename to snapshot/testutil/helpers.go
index 27e0d9a..9ae954b 100644
--- a/snapshot/common_test.go
+++ b/snapshot/testutil/helpers.go
@@ -1,4 +1,4 @@
-package snapshot
+package testutil
 
 import (
 	"os/exec"
@@ -7,13 +7,13 @@ import (
 	"github.com/docker/containerd"
 )
 
-func unmountAll(t *testing.T, mounts []containerd.Mount) {
+func UnmountAll(t *testing.T, mounts []containerd.Mount) {
 	for _, mount := range mounts {
-		unmount(t, mount.Target)
+		Unmount(t, mount.Target)
 	}
 }
 
-func unmount(t *testing.T, mountPoint string) {
+func Unmount(t *testing.T, mountPoint string) {
 	t.Log("unmount", mountPoint)
 	umount := exec.Command("umount", mountPoint)
 	err := umount.Run()