diff -u b/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
--- b/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2407,7 +2407,8 @@
  * @param Symfony\Component\DependencyInjection\Container $new_container
  *   A new container instance to replace the current.
  * @param bool $rebuild
- *   (optional) Internal use only. Whether to build a new minimal container.
+ *   (optional) Internal use only. Whether to enforce a rebuild of the container.
+ *   Used by the testing framework to inject a fresh container for unit tests.
  *
  * @return Symfony\Component\DependencyInjection\Container
  *   The instance of the Container used to set up and maintain object
@@ -2418,8 +2419,11 @@
   // which to reinitialize the stored objects, so a drupal_static_reset() call
   // would leave Drupal in a nonfunctional state.
   static $container = NULL;
-  if (isset($new_container) || $rebuild) {
-    $container = $rebuild ? NULL : $new_container;
+  if ($rebuild) {
+    $container = NULL;
+  }
+  if (isset($new_container)) {
+    $container = $new_container;
   }
   if (!isset($container)) {
     // Return a ContainerBuilder instance with the bare essentials needed for any
@@ -2428,27 +2432,34 @@
     // requests.
     $container = new ContainerBuilder();
 
-    $container->register('config.cachedstorage.delegate', 'Drupal\Core\Config\FileStorage')
-      ->addArgument(config_get_config_directory());
-    $container->register('config.cachedstorage.cache')
+    // Register active configuration storage.
+    $container
+      ->register('config.cachedstorage.storage', 'Drupal\Core\Config\FileStorage')
+      ->addArgument(config_get_config_directory(CONFIG_ACTIVE_DIRECTORY));
+    // @todo Replace this with a cache.factory service plus 'config' argument.
+    $container
+      ->register('cache.config')
       ->setFactoryClass('Drupal\Core\Cache\CacheFactory')
       ->setFactoryMethod('get')
       ->addArgument('config');
-    $container->register('config.storage.staging', 'Drupal\Core\Config\FileStorage')
-      ->addArgument(config_get_config_directory(CONFIG_STAGING_DIRECTORY));
-    $container->register('config.storage', 'Drupal\Core\Config\CachedStorage')
-      ->addArgument(new Reference('config.cachedstorage.delegate'))
-      ->addArgument(new Reference('config.cachedstorage.cache'));
 
+    $container
+      ->register('config.storage', 'Drupal\Core\Config\CachedStorage')
+      ->addArgument(new Reference('config.cachedstorage.storage'))
+      ->addArgument(new Reference('cache.config'));
+
+    // Register configuration object factory.
     $container->register('config.subscriber.globalconf', 'Drupal\Core\EventSubscriber\ConfigGlobalOverrideSubscriber');
     $container->register('dispatcher', 'Symfony\Component\EventDispatcher\EventDispatcher')
       ->addMethodCall('addSubscriber', array(new Reference('config.subscriber.globalconf')));
-
-    // Register configuration object factory.
     $container->register('config.factory', 'Drupal\Core\Config\ConfigFactory')
       ->addArgument(new Reference('config.storage'))
       ->addArgument(new Reference('dispatcher'));
 
+    // Register staging configuration storage.
+    $container
+      ->register('config.storage.staging', 'Drupal\Core\Config\FileStorage')
+      ->addArgument(config_get_config_directory(CONFIG_STAGING_DIRECTORY));
   }
   return $container;
 }
diff -u b/core/includes/cache.inc b/core/includes/cache.inc
--- b/core/includes/cache.inc
+++ b/core/includes/cache.inc
@@ -1,12 +1,12 @@
 <?php
 
-use Drupal\Core\Cache\CacheFactory;
-
 /**
  * @file
  * Functions and interfaces for cache handling.
  */
 
+use Drupal\Core\Cache\CacheFactory;
+
 /**
  * Instantiates and statically caches the correct class for a cache bin.
  *
diff -u b/core/includes/install.core.inc b/core/includes/install.core.inc
--- b/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -280,8 +280,8 @@
   // If it is not, replace the configuration storage with the InstallStorage
   // implementation, for the following reasons:
   // - The first call into drupal_container() will try to set up the regular
-  //   runtime configuration storage, using the CachedFileStorage. The storage
-  //   controller options require to pass in the config directory name, but that
+  //   runtime configuration storage, using the CachedStorage. The storage
+  //   controller requires to pass in the active config directory name, but that
   //   directory does not exist yet.
   // - The installer outputs maintenance theme pages and performs many other
   //   operations, which try to load configuration. Since there is no active
@@ -296,8 +296,8 @@
   // This override is reverted as soon as the config directory has been set up
   // successfully.
   // @see drupal_install_config_directory()
-  // @todo Move this into a proper Drupal\Core\DependencyInjection\InstallContainerBuilder.
   if (!$install_state['config_verified']) {
+    // @todo Move into a proper Drupal\Core\DependencyInjection\InstallContainerBuilder.
     $container = new ContainerBuilder();
 
     $container->register('dispatcher', 'Symfony\Component\EventDispatcher\EventDispatcher');
@@ -1093,7 +1093,7 @@
 
   // We have valid configuration directories in settings.php.
   // Reset the service container, so the config.storage service will use the
-  // actual cached storage for installing configuration.
+  // actual active storage for installing configuration.
   drupal_container(NULL, TRUE);
 
   // Indicate that the settings file has been verified, and check the database
diff -u b/core/includes/install.inc b/core/includes/install.inc
--- b/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -313,10 +313,9 @@
   if (!isset($config_directories[$type])) {
     return FALSE;
   }
-  // config_get_config_directory() throws an exception when the $type passed
-  // it doesn't exist yet in $config_directories. This can happen if there is
-  // a prepared settings.php that defines $config_directories already and the
-  // directories do not exist yet.
+  // config_get_config_directory() throws an exception when the passed $type
+  // does not exist in $config_directories. This can happen if there is a
+  // prepared settings.php that defines $config_directories already.
   try {
     $config_directory = config_get_config_directory($type);
     if (is_dir($config_directory) && is_writable($config_directory)) {
diff -u b/core/lib/Drupal/Core/Cache/CacheFactory.php b/core/lib/Drupal/Core/Cache/CacheFactory.php
--- b/core/lib/Drupal/Core/Cache/CacheFactory.php
+++ b/core/lib/Drupal/Core/Cache/CacheFactory.php
@@ -2,10 +2,47 @@
 
+/**
+ * @file
+ * Contains Drupal\Core\Cache\CacheFactory.
+ */
+
 namespace Drupal\Core\Cache;
 
+/**
+ * Defines the cache backend factory.
+ */
 class CacheFactory {
+
+  /**
+   * Instantiates a cache backend class for a given cache bin.
+   *
+   * By default, this returns an instance of the
+   * Drupal\Core\Cache\DatabaseBackend class.
+   *
+   * Classes implementing Drupal\Core\Cache\CacheBackendInterface can register
+   * themselves both as a default implementation and for specific bins.
+   *
+   * @param string $bin
+   *   The cache bin for which a cache backend object should be returned.
+   *
+   * @return Drupal\Core\Cache\CacheBackendInterface
+   *   The cache backend object associated with the specified bin.
+   */
   static function get($bin) {
-    $cache_backends = cache_get_backends();
-    $class = isset($cache_backends[$bin]) ? $cache_backends[$bin] : $cache_backends['cache'];
+    // @todo Improve how cache backend classes are defined. Cannot be
+    //   configuration, since e.g. the CachedStorage config storage controller
+    //   requires the definition in its constructor already.
+    global $conf;
+    $cache_backends = isset($conf['cache_classes']) ? $conf['cache_classes'] : array();
+
+    // Check whether there is a custom class defined for the requested bin and
+    // default to the DatabaseBackend otherwise.
+    if (isset($cache_backends[$bin])) {
+      $class = $cache_backends[$bin];
+    }
+    else {
+      $class = 'Drupal\Core\Cache\DatabaseBackend';
+    }
     return new $class($bin);
   }
+
 }
diff -u b/core/lib/Drupal/Core/Config/CachedStorage.php b/core/lib/Drupal/Core/Config/CachedStorage.php
--- b/core/lib/Drupal/Core/Config/CachedStorage.php
+++ b/core/lib/Drupal/Core/Config/CachedStorage.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains Drupal\Core\Config\CacheStorage.
+ * Contains Drupal\Core\Config\CachedStorage.
  */
 
 namespace Drupal\Core\Config;
@@ -12,18 +12,18 @@
 /**
  * Defines the cached storage controller.
  *
- * The class gets another storage and a cache backend injected. It tries to
- * read from the cache and if it misses, delegates the read. It also handles
- * cache invalidation.
+ * The class gets another storage and a cache backend injected. It reads from
+ * the cache and delegates the read to the storage on a cache miss. It also
+ * handles cache invalidation.
  */
 class CachedStorage implements StorageInterface {
 
   /**
-   * The storage to be cached.
+   * The configuration storage to be cached.
    *
    * @var Drupal\Core\Config\StorageInterface
    */
-  protected $delegate;
+  protected $storage;
 
   /**
    * The instantiated Cache backend.
@@ -33,10 +33,15 @@
   protected $cache;
 
   /**
-   * Implements Drupal\Core\Config\StorageInterface::__construct().
+   * Constructs a new CachedStorage controller.
+   *
+   * @param Drupal\Core\Config\StorageInterface $storage
+   *   A configuration storage controller to be cached.
+   * @param Drupal\Core\Cache\CacheBackendInterface $cache
+   *   A cache backend instance to use for caching.
    */
-  public function __construct(StorageInterface $delegate, CacheBackendInterface $cache) {
-    $this->delegate = $delegate;
+  public function __construct(StorageInterface $storage, CacheBackendInterface $cache) {
+    $this->storage = $storage;
     $this->cache = $cache;
   }
 
@@ -44,7 +49,9 @@
    * Implements Drupal\Core\Config\StorageInterface::exists().
    */
   public function exists($name) {
-    return $this->delegate->exists($name);
+    // A single storage lookup is faster than a cache lookup and possibly
+    // subsequent storage lookup.
+    return $this->storage->exists($name);
   }
 
   /**
@@ -52,18 +59,26 @@
    */
   public function read($name) {
     if ($cache = $this->cache->get($name)) {
-      return $cache->data;
+      // The cache backend supports primitive data types, but only an array
+      // represents valid config object data.
+      if (is_array($cache->data)) {
+        return $cache->data;
+      }
+    }
+    // Read from the storage on a cache miss and cache the data, if any.
+    $data = $this->storage->read($name);
+    if ($data !== FALSE) {
+      $this->cache->set($name, $data, CacheBackendInterface::CACHE_PERMANENT, array('config' => array($name)));
     }
-    return $this->delegate->read($name);
+    return $data;
   }
 
   /**
    * Implements Drupal\Core\Config\StorageInterface::write().
    */
   public function write($name, array $data) {
-    $this->cache->set($name, $data, CacheBackendInterface::CACHE_PERMANENT, array('config' => array($name)));
-    $this->delegate->write($name, $data);
-    return TRUE;
+    $this->cache->delete($name);
+    return $this->storage->write($name, $data);
   }
 
   /**
@@ -71,8 +86,7 @@
    */
   public function delete($name) {
     $this->cache->delete($name);
-    $this->delegate->delete($name);
-    return TRUE;
+    return $this->storage->delete($name);
   }
 
   /**
@@ -81,26 +95,21 @@
   public function rename($name, $new_name) {
     $this->cache->delete($name);
     $this->cache->delete($new_name);
-    $this->delegate->rename($name, $new_name);
-    return TRUE;
+    return $this->storage->rename($name, $new_name);
   }
 
   /**
    * Implements Drupal\Core\Config\StorageInterface::encode().
    */
   public static function encode($data) {
-    return serialize($data);
+    return $this->storage->encode($data);
   }
 
   /**
    * Implements Drupal\Core\Config\StorageInterface::decode().
-   *
-   * @throws ErrorException
-   *   unserialize() triggers E_NOTICE if the string cannot be unserialized.
    */
   public static function decode($raw) {
-    $data = @unserialize($raw);
-    return is_array($data) ? $data : FALSE;
+    return $this->storage->decode($raw);
   }
 
   /**
@@ -110,5 +119,5 @@
    */
   public function listAll($prefix = '') {
-    return $this->delegate->listAll($prefix);
+    return $this->storage->listAll($prefix);
   }
 }
diff -u /dev/null b/core/lib/Drupal/Core/Config/DatabaseStorage.php
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/DatabaseStorage.php
@@ -0,0 +1,163 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Config\DatabaseStorage.
+ */
+
+namespace Drupal\Core\Config;
+
+use Drupal\Core\Database\Database;
+use Drupal\Core\Database\Connection;
+use Exception;
+
+/**
+ * Defines the Database storage controller.
+ */
+class DatabaseStorage implements StorageInterface {
+
+  /**
+   * The database connection.
+   *
+   * @var Drupal\Core\Database\Connection
+   */
+  protected $connection;
+
+  /**
+   * The database table name.
+   *
+   * @var string
+   */
+  protected $table;
+
+  /**
+   * Additional database connection options to use in queries.
+   *
+   * @var array
+   */
+  protected $options = array();
+
+  /**
+   * Constructs a new DatabaseStorage controller.
+   *
+   * @param Drupal\Core\Database\Connection $connection
+   *   A Database connection to use for reading and writing configuration data.
+   * @param string $table
+   *   A database table name to store configuration data in.
+   * @param array $options
+   *   (optional) Any additional database connection options to use in queries.
+   */
+  public function __construct(Connection $connection, $table, array $options = array()) {
+    $this->connection = $connection;
+    $this->table = $table;
+    $this->options = $options;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::exists().
+   */
+  public function exists($name) {
+    return (bool) $this->connection->queryRange('SELECT 1 FROM {' . $this->table . '} WHERE name = :name', 0, 1, array(
+      ':name' => $name,
+    ), $this->options)->fetchField();
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::read().
+   *
+   * @throws PDOException
+   * @throws Drupal\Core\Database\DatabaseExceptionWrapper
+   *   Only thrown in case $this->options['throw_exception'] is TRUE.
+   */
+  public function read($name) {
+    $data = FALSE;
+    // There are situations, like in the installer, where we may attempt a
+    // read without actually having the database available. In this case,
+    // catch the exception and just return an empty array so the caller can
+    // handle it if need be.
+    try {
+      $raw = $this->connection->query('SELECT data FROM {' . $this->table . '} WHERE name = :name', array(':name' => $name), $this->options)->fetchField();
+      if ($raw !== FALSE) {
+        $data = $this->decode($raw);
+      }
+    }
+    catch (Exception $e) {
+    }
+    return $data;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::write().
+   *
+   * @throws PDOException
+   *
+   * @todo Ignore slave targets for data manipulation operations.
+   */
+  public function write($name, array $data) {
+    $data = $this->encode($data);
+    $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+    return (bool) $this->connection->merge($this->table, $options)
+      ->key(array('name' => $name))
+      ->fields(array('data' => $data))
+      ->execute();
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::delete().
+   *
+   * @throws PDOException
+   *
+   * @todo Ignore slave targets for data manipulation operations.
+   */
+  public function delete($name) {
+    $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+    return (bool) $this->connection->delete($this->table, $options)
+      ->condition('name', $name)
+      ->execute();
+  }
+
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::rename().
+   *
+   * @throws PDOException
+   */
+  public function rename($name, $new_name) {
+    $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+    return (bool) $this->connection->update($this->table, $options)
+      ->fields(array('name' => $new_name))
+      ->condition('name', $name)
+      ->execute();
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::encode().
+   */
+  public static function encode($data) {
+    return serialize($data);
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::decode().
+   *
+   * @throws ErrorException
+   *   unserialize() triggers E_NOTICE if the string cannot be unserialized.
+   */
+  public static function decode($raw) {
+    $data = @unserialize($raw);
+    return is_array($data) ? $data : FALSE;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::listAll().
+   *
+   * @throws PDOException
+   * @throws Drupal\Core\Database\DatabaseExceptionWrapper
+   *   Only thrown in case $this->options['throw_exception'] is TRUE.
+   */
+  public function listAll($prefix = '') {
+    return $this->connection->query('SELECT name FROM {' . $this->table . '} WHERE name LIKE :name', array(
+      ':name' => db_like($prefix) . '%',
+    ), $this->options)->fetchCol();
+  }
+}
diff -u b/core/lib/Drupal/Core/Config/FileStorage.php b/core/lib/Drupal/Core/Config/FileStorage.php
--- b/core/lib/Drupal/Core/Config/FileStorage.php
+++ b/core/lib/Drupal/Core/Config/FileStorage.php
@@ -22,7 +22,10 @@
   protected $directory = '';
 
   /**
-   * Implements Drupal\Core\Config\StorageInterface::__construct().
+   * Constructs a new FileStorage controller.
+   *
+   * @param string $directory
+   *   A directory path to use for reading and writing of configuration files.
    */
   public function __construct($directory) {
     $this->directory = $directory;
diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigFileContentTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigFileContentTest.php
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigFileContentTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigFileContentTest.php
@@ -200,7 +200,7 @@
     );
 
     // Encode and write, and reload and decode the configuration data.
-    $filestorage = new FileStorage(config_get_config_directory());
+    $filestorage = new FileStorage($this->configDirectories[CONFIG_ACTIVE_DIRECTORY]);
     $filestorage->write($name, $config_data);
     $config_parsed = $filestorage->read($name);
 
diff -u /dev/null b/core/modules/config/lib/Drupal/config/Tests/Storage/DatabaseStorageTest.php
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/Storage/DatabaseStorageTest.php
@@ -0,0 +1,72 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config\Tests\Storage\DatabaseStorageTest.
+ */
+
+namespace Drupal\config\Tests\Storage;
+
+use Drupal\Core\Config\DatabaseStorage;
+
+/**
+ * Tests DatabaseStorage controller operations.
+ */
+class DatabaseStorageTest extends ConfigStorageTestBase {
+  public static function getInfo() {
+    return array(
+      'name' => 'DatabaseStorage controller operations',
+      'description' => 'Tests DatabaseStorage controller operations.',
+      'group' => 'Configuration',
+    );
+  }
+
+  function setUp() {
+    parent::setUp();
+
+    $schema['config'] = array(
+      'description' => 'Default active store for the configuration system.',
+      'fields' => array(
+        'name' => array(
+          'description' => 'The identifier for the configuration entry, such as module.example (the name of the file, minus the file extension).',
+          'type' => 'varchar',
+          'length' => 255,
+          'not null' => TRUE,
+          'default' => '',
+        ),
+        'data' => array(
+          'description' => 'The raw data for this configuration entry.',
+          'type' => 'blob',
+          'not null' => TRUE,
+          'size' => 'big',
+          'translatable' => TRUE,
+        ),
+      ),
+      'primary key' => array('name'),
+    );
+    db_create_table('config', $schema['config']);
+
+    $this->storage = new DatabaseStorage($this->container->get('database'), 'config');
+    $this->invalidStorage = new DatabaseStorage($this->container->get('database'), 'invalid');
+
+    // ::listAll() verifications require other configuration data to exist.
+    $this->storage->write('system.performance', array());
+  }
+
+  protected function read($name) {
+    $data = db_query('SELECT data FROM {config} WHERE name = :name', array(':name' => $name))->fetchField();
+    return unserialize($data);
+  }
+
+  protected function insert($name, $data) {
+    db_insert('config')->fields(array('name' => $name, 'data' => $data))->execute();
+  }
+
+  protected function update($name, $data) {
+    db_update('config')->fields(array('data' => $data))->condition('name', $name)->execute();
+  }
+
+  protected function delete($name) {
+    db_delete('config')->condition('name', $name)->execute();
+  }
+}
diff -u b/core/modules/config/lib/Drupal/config/Tests/Storage/FileStorageTest.php b/core/modules/config/lib/Drupal/config/Tests/Storage/FileStorageTest.php
--- b/core/modules/config/lib/Drupal/config/Tests/Storage/FileStorageTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/Storage/FileStorageTest.php
@@ -24,7 +24,7 @@
 
   function setUp() {
     parent::setUp();
-    $this->storage = new FileStorage(config_get_config_directory());
+    $this->storage = new FileStorage($this->configDirectories[CONFIG_ACTIVE_DIRECTORY]);
     $this->invalidStorage = new FileStorage($this->configDirectories[CONFIG_ACTIVE_DIRECTORY] . '/nonexisting');
 
     // FileStorage::listAll() requires other configuration data to exist.
diff -u b/core/modules/entity/lib/Drupal/entity/Entity.php b/core/modules/entity/lib/Drupal/entity/Entity.php
--- b/core/modules/entity/lib/Drupal/entity/Entity.php
+++ b/core/modules/entity/lib/Drupal/entity/Entity.php
@@ -289,2 +289,3 @@
   }
+
 }
diff -u b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
--- b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -727,8 +727,7 @@
     }
 
     // Reset and create a new service container.
-    drupal_container(NULL, TRUE);
-    $this->container = drupal_container();
+    $this->container = drupal_container(NULL, TRUE);
 
     $this->configDirectories = array();
     include_once DRUPAL_ROOT . '/core/includes/install.inc';
diff -u b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
--- b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -674,6 +674,9 @@
     // Symfony\Component\HttpKernel\handle(), this kernel needs manual booting
     // as it is not used to handle a request.
     $this->kernel->boot();
+    // The DrupalKernel does not update the container in drupal_container(), but
+    // replaces it with a new object. We therefore need to replace the minimal
+    // boostrap container that has been set up by TestBase::prepareEnvironment().
     $this->container = drupal_container();
 
     // Reset/rebuild all data structures after enabling the modules.
diff -u b/core/modules/system/system.install b/core/modules/system/system.install
--- b/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -1550,7 +1550,7 @@
  * Creates {cache_config} cache table for the new configuration system.
  */
 function system_update_8003() {
-  $cache_update = array(
+  $spec = array(
     'description' =>  'Cache table for configuration data.',
     'fields' => array(
       'cid' => array(
@@ -1603,7 +1603,7 @@
     ),
     'primary key' => array('cid'),
   );
-  db_create_table('cache_config', $cache_update);
+  db_create_table('cache_config', $spec);
 }
 
 /**