diff --git a/src/storage/interface.js b/src/storage/interface.js
index 4a0ddaf5a..a589b3371 100644
--- a/src/storage/interface.js
+++ b/src/storage/interface.js
@@ -7,17 +7,13 @@
 // -------------------------------------------
 
 exports = module.exports = {
-    backupBegin: backupBegin,
-    backupDirectory: backupDirectory,
-    backupFinalize: backupFinalize,
-
-    getRestoreUrl: getRestoreUrl,
-    getAppRestoreConfig: getAppRestoreConfig,
-    getLocalFilePath: getLocalFilePath,
-
-    copyObject: copyObject,
+    backup: backup,
+    restore: restore,
+    copyBackup: copyBackup,
     removeBackup: removeBackup,
 
+    getDownloadStream: getDownloadStream,
+
     backupDone: backupDone,
 
     testConfig: testConfig
@@ -25,9 +21,10 @@ exports = module.exports = {
 
 var assert = require('assert');
 
-function backupBegin(apiConfig, backupId, callback) {
+function backup(apiConfig, backupId, sourceDirectories, callback) {
     assert.strictEqual(typeof apiConfig, 'object');
     assert.strictEqual(typeof backupId, 'string');
+    assert(Array.isArray(sourceDirectories));
     assert.strictEqual(typeof callback, 'function');
 
     // Result: none
@@ -35,11 +32,10 @@ function backupBegin(apiConfig, backupId, callback) {
     callback(new Error('not implemented'));
 }
 
-function backupDirectory(apiConfig, backupId, source, destination, callback) {
+function restore(apiConfig, backupId, destinationDirectories, callback) {
     assert.strictEqual(typeof apiConfig, 'object');
     assert.strictEqual(typeof backupId, 'string');
-    assert.strictEqual(typeof source, 'string');
-    assert.strictEqual(typeof destination, 'string');
+    assert(Array.isArray(destinationDirectories));
     assert.strictEqual(typeof callback, 'function');
 
     // Result: none
@@ -47,55 +43,10 @@ function backupDirectory(apiConfig, backupId, source, destination, callback) {
     callback(new Error('not implemented'));
 }
 
-function backupFinalize(apiConfig, backupId, callback) {
+function copyBackup(apiConfig, oldBackupId, newBackupId, callback) {
     assert.strictEqual(typeof apiConfig, 'object');
-    assert.strictEqual(typeof backupId, 'string');
-    assert.strictEqual(typeof callback, 'function');
-
-    // Result: none
-
-    callback(new Error('not implemented'));
-}
-
-function getRestoreUrl(apiConfig, filename, callback) {
-    assert.strictEqual(typeof apiConfig, 'object');
-    assert.strictEqual(typeof filename, 'string');
-    assert.strictEqual(typeof callback, 'function');
-
-    // Result: { url: <restoreUrl>, sha1: <optional> }
-    // The resulting url must work with curl as it is passed into start.sh and restoreapp.sh
-
-    callback(new Error('not implemented'));
-}
-
-function getAppRestoreConfig(apiConfig, backupId, callback) {
-    assert.strictEqual(typeof apiConfig, 'object');
-    assert.strictEqual(typeof backupId, 'string');
-    assert.strictEqual(typeof callback, 'function');
-
-    // var configFilename = backupId.replace(/\.tar\.gz$/, '.json');
-
-    // Result: {} <- Backup config object from .json file
-    // The resulting url must work with curl as it is passed into start.sh and restoreapp.sh
-
-    callback(new Error('not implemented'));
-}
-
-function getLocalFilePath(apiConfig, filename, callback) {
-    assert.strictEqual(typeof apiConfig, 'object');
-    assert.strictEqual(typeof filename, 'string');
-    assert.strictEqual(typeof callback, 'function');
-
-    // Result: { filePath: <localFilePath> }
-    // The resulting filePath is a local path to the backup file
-
-    callback(new Error('not implemented'));
-}
-
-function copyObject(apiConfig, from, to, callback) {
-    assert.strictEqual(typeof apiConfig, 'object');
-    assert.strictEqual(typeof from, 'string');
-    assert.strictEqual(typeof to, 'string');
+    assert.strictEqual(typeof oldBackupId, 'string');
+    assert.strictEqual(typeof newBackupId, 'string');
     assert.strictEqual(typeof callback, 'function');
 
     // Result: none
@@ -114,11 +65,21 @@ function removeBackup(apiConfig, backupId, appBackupIds, callback) {
     callback(new Error('not implemented'));
 }
 
+function getDownloadStream(apiConfig, backupId, callback) {
+    assert.strictEqual(typeof apiConfig, 'object');
+    assert.strictEqual(typeof backupId, 'string');
+    assert.strictEqual(typeof callback, 'function');
+
+    // Result: ReadStream to a tar.gz (not encrypted)
+
+    callback(new Error('not implemented'));
+}
+
 function testConfig(apiConfig, callback) {
     assert.strictEqual(typeof apiConfig, 'object');
     assert.strictEqual(typeof callback, 'function');
 
-    // Result: none
+    // Result: none - first callback argument error if config does not pass the test
 
     callback(new Error('not implemented'));
 }