diff --git a/pkg/blobserver/diskpacked/diskpacked.go b/pkg/blobserver/diskpacked/diskpacked.go
index 2e3c2db1f..bff0d15f0 100644
--- a/pkg/blobserver/diskpacked/diskpacked.go
+++ b/pkg/blobserver/diskpacked/diskpacked.go
@@ -121,12 +121,12 @@ func New(dir string) (blobserver.Storage, error) {
 		// TODO: detect existing max size from size of files, if obvious,
 		// and set maxSize to that?
 	}
-	return newStorage(dir, maxSize)
+	return newStorage(dir, maxSize, nil)
 }
 
 // newStorage returns a new storage in path root with the given maxFileSize,
 // or defaultMaxFileSize (512MB) if <= 0
-func newStorage(root string, maxFileSize int64) (s *storage, err error) {
+func newStorage(root string, maxFileSize int64, indexConf jsonconfig.Obj) (s *storage, err error) {
 	fi, err := os.Stat(root)
 	if os.IsNotExist(err) {
 		return nil, fmt.Errorf("storage root %q doesn't exist", root)
@@ -137,7 +137,12 @@ func newStorage(root string, maxFileSize int64) (s *storage, err error) {
 	if !fi.IsDir() {
 		return nil, fmt.Errorf("storage root %q exists but is not a directory.", root)
 	}
-	index, err := kvfile.NewStorage(filepath.Join(root, indexKV))
+	var index sorted.KeyValue
+	if indexConf != nil {
+		index, err = sorted.NewKeyValue(indexConf)
+	} else {
+		index, err = kvfile.NewStorage(filepath.Join(root, indexKV))
+	}
 	if err != nil {
 		return nil, err
 	}
@@ -171,12 +176,15 @@ func newStorage(root string, maxFileSize int64) (s *storage, err error) {
 }
 
 func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (storage blobserver.Storage, err error) {
-	path := config.RequiredString("path")
-	maxFileSize := config.OptionalInt("maxFileSize", 0)
+	var (
+		path        = config.RequiredString("path")
+		maxFileSize = config.OptionalInt("maxFileSize", 0)
+		indexConf   = config.OptionalObject("metaIndex")
+	)
 	if err := config.Validate(); err != nil {
 		return nil, err
 	}
-	return newStorage(path, int64(maxFileSize))
+	return newStorage(path, int64(maxFileSize), indexConf)
 }
 
 func init() {
diff --git a/pkg/blobserver/diskpacked/diskpacked_test.go b/pkg/blobserver/diskpacked/diskpacked_test.go
index 7a82431ad..8d03f92be 100644
--- a/pkg/blobserver/diskpacked/diskpacked_test.go
+++ b/pkg/blobserver/diskpacked/diskpacked_test.go
@@ -24,16 +24,27 @@ import (
 
 	"camlistore.org/pkg/blobserver"
 	"camlistore.org/pkg/blobserver/storagetest"
+	"camlistore.org/pkg/jsonconfig"
 	"camlistore.org/pkg/test"
 )
 
 func newTempDiskpacked(t *testing.T) (sto blobserver.Storage, cleanup func()) {
+	return newTempDiskpackedWithIndex(t, nil)
+}
+
+func newTempDiskpackedMemory(t *testing.T) (sto blobserver.Storage, cleanup func()) {
+	return newTempDiskpackedWithIndex(t, jsonconfig.Obj{
+		"type": "memory",
+	})
+}
+
+func newTempDiskpackedWithIndex(t *testing.T, indexConf jsonconfig.Obj) (sto blobserver.Storage, cleanup func()) {
 	dir, err := ioutil.TempDir("", "diskpacked-test")
 	if err != nil {
 		t.Fatal(err)
 	}
 	t.Logf("diskpacked test dir is %q", dir)
-	s, err := newStorage(dir, 1<<20)
+	s, err := newStorage(dir, 1<<20, indexConf)
 	if err != nil {
 		t.Fatalf("newStorage: %v", err)
 	}
@@ -47,6 +58,10 @@ func TestDiskpacked(t *testing.T) {
 	storagetest.Test(t, newTempDiskpacked)
 }
 
+func TestDiskpackedAltIndex(t *testing.T) {
+	storagetest.Test(t, newTempDiskpackedMemory)
+}
+
 func TestDoubleReceive(t *testing.T) {
 	sto, cleanup := newTempDiskpacked(t)
 	defer cleanup()