diff --git a/core/includes/errors.inc b/core/includes/errors.inc
index 2365e2a..cba08e2 100644
--- a/core/includes/errors.inc
+++ b/core/includes/errors.inc
@@ -10,22 +10,22 @@ use Symfony\Component\HttpFoundation\Response;
 /**
  * Error reporting level: display no errors.
  */
-const ERROR_REPORTING_HIDE = 0;
+const ERROR_REPORTING_HIDE = 'hide';
 
 /**
  * Error reporting level: display errors and warnings.
  */
-const ERROR_REPORTING_DISPLAY_SOME = 1;
+const ERROR_REPORTING_DISPLAY_SOME = 'some';
 
 /**
  * Error reporting level: display all messages.
  */
-const ERROR_REPORTING_DISPLAY_ALL = 2;
+const ERROR_REPORTING_DISPLAY_ALL = 'all';
 
 /**
  * Error reporting level: display all messages, plus backtrace information.
  */
-const ERROR_REPORTING_DISPLAY_VERBOSE = 3;
+const ERROR_REPORTING_DISPLAY_VERBOSE = 'verbose';
 
 /**
  * Maps PHP error constants to watchdog severity levels.
@@ -172,7 +172,7 @@ function _drupal_render_exception_safe($exception) {
  *   TRUE if an error should be displayed.
  */
 function error_displayable($error = NULL) {
-  $error_level = variable_get('error_level', ERROR_REPORTING_DISPLAY_ALL);
+  $error_level = config('system.logging')->get('error_level');
   $updating = (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update');
   $all_errors_displayed = ($error_level == ERROR_REPORTING_DISPLAY_ALL) ||
     ($error_level == ERROR_REPORTING_DISPLAY_VERBOSE);
diff --git a/core/modules/dblog/config/dblog.settings.yml b/core/modules/dblog/config/dblog.settings.yml
new file mode 100644
index 0000000..88add88
--- /dev/null
+++ b/core/modules/dblog/config/dblog.settings.yml
@@ -0,0 +1 @@
+row_limit: 1000
diff --git a/core/modules/dblog/dblog.install b/core/modules/dblog/dblog.install
index 23f85ba..919bab3 100644
--- a/core/modules/dblog/dblog.install
+++ b/core/modules/dblog/dblog.install
@@ -92,8 +92,21 @@ function dblog_schema() {
 }
 
 /**
- * Implements hook_uninstall().
+ * @defgroup updates-7.x-to-8.x Updates from 7.x to 8.x
+ * @{
+ * Update functions from 7.x to 8.x.
  */
-function dblog_uninstall() {
-  variable_del('dblog_row_limit');
+
+/**
+ * Update settings to the new configuration system.
+ */
+function dblog_update_8000() {
+  update_variables_to_config('dblog.settings', array(
+    'dblog_row_limit' => 'row_limit',
+  ));
 }
+
+/**
+ * @} End of "defgroup updates-7.x-to-8.x"
+ * The next series of updates should start at 9000.
+ */
diff --git a/core/modules/dblog/dblog.module b/core/modules/dblog/dblog.module
index a43e0a5..25ad6c5 100644
--- a/core/modules/dblog/dblog.module
+++ b/core/modules/dblog/dblog.module
@@ -102,7 +102,7 @@ function dblog_init() {
  */
 function dblog_cron() {
   // Cleanup the watchdog table.
-  $row_limit = variable_get('dblog_row_limit', 1000);
+  $row_limit = config('dblog.settings')->get('row_limit');
 
   // For row limit n, get the wid of the nth row in descending wid order.
   // Counting the most recent n rows avoids issues with wid number sequences,
@@ -163,11 +163,21 @@ function dblog_form_system_logging_settings_alter(&$form, $form_state) {
   $form['dblog_row_limit'] = array(
     '#type' => 'select',
     '#title' => t('Database log messages to keep'),
-    '#default_value' => variable_get('dblog_row_limit', 1000),
+    '#default_value' => config('dblog.settings')->get('row_limit'),
     '#options' => array(0 => t('All')) + drupal_map_assoc(array(100, 1000, 10000, 100000, 1000000)),
     '#description' => t('The maximum number of messages to keep in the database log. Requires a <a href="@cron">cron maintenance task</a>.', array('@cron' => url('admin/reports/status')))
   );
-  $form['actions']['#weight'] = 1;
+
+  $form['#submit'][] = 'dblog_logging_settings_submit';
+}
+
+/**
+ * Form submission handler for system_logging_settings().
+ *
+ * @see dblog_form_system_logging_settings_alter()
+ */
+function dblog_logging_settings_submit($form, &$form_state) {
+  config('dblog.settings')->set('row_limit', $form_state['values']['dblog_row_limit'])->save();
 }
 
 /**
diff --git a/core/modules/dblog/lib/Drupal/dblog/Tests/DBLogTest.php b/core/modules/dblog/lib/Drupal/dblog/Tests/DBLogTest.php
index 17667c9..fd1e9af 100644
--- a/core/modules/dblog/lib/Drupal/dblog/Tests/DBLogTest.php
+++ b/core/modules/dblog/lib/Drupal/dblog/Tests/DBLogTest.php
@@ -65,11 +65,8 @@ class DBLogTest extends WebTestBase {
     $this->assertResponse(200);
 
     // Check row limit variable.
-    $current_limit = variable_get('dblog_row_limit', 1000);
+    $current_limit = config('dblog.settings')->get('row_limit');
     $this->assertTrue($current_limit == $row_limit, t('[Cache] Row limit variable of @count equals row limit of @limit', array('@count' => $current_limit, '@limit' => $row_limit)));
-    // Verify dblog row limit equals specified row limit.
-    $current_limit = unserialize(db_query("SELECT value FROM {variable} WHERE name = :dblog_limit", array(':dblog_limit' => 'dblog_row_limit'))->fetchField());
-    $this->assertTrue($current_limit == $row_limit, t('[Variable table] Row limit variable of @count equals row limit of @limit', array('@count' => $current_limit, '@limit' => $row_limit)));
   }
 
   /**
diff --git a/core/modules/syslog/config/syslog.settings.yml b/core/modules/syslog/config/syslog.settings.yml
new file mode 100644
index 0000000..1aa5b90
--- /dev/null
+++ b/core/modules/syslog/config/syslog.settings.yml
@@ -0,0 +1,3 @@
+identity: drupal
+facility: ''
+format: '!base_url|!timestamp|!type|!ip|!request_uri|!referer|!uid|!link|!message'
diff --git a/core/modules/syslog/syslog.install b/core/modules/syslog/syslog.install
index 12ff4fb..7ae9f89 100644
--- a/core/modules/syslog/syslog.install
+++ b/core/modules/syslog/syslog.install
@@ -6,10 +6,32 @@
  */
 
 /**
- * Implements hook_uninstall().
+ * Implements hook_install().
  */
-function syslog_uninstall() {
-  variable_del('syslog_identity');
-  variable_del('syslog_facility');
-  variable_del('syslog_format');
+function syslog_install() {
+  // The default facility setting depends on the operating system, so it needs
+  // to be set dynamically during installation.
+  config('syslog.settings')->set('facility', defined('LOG_LOCAL0') ? LOG_LOCAL0 : LOG_USER)->save();
 }
+
+/**
+ * @defgroup updates-7.x-to-8.x Updates from 7.x to 8.x
+ * @{
+ * Update functions from 7.x to 8.x.
+ */
+
+/**
+ * Update settings to the new configuration system.
+ **/
+function syslog_update_8000() {
+  update_variables_to_config('syslog.settings', array(
+    'syslog_identity' => 'identity',
+    'syslog_facility' => 'facility',
+    'syslog_format' => 'format',
+  ));
+}
+
+/**
+ * @} End of "defgroup updates-7.x-to-8.x"
+ * The next series of updates should start at 9000.
+ */
diff --git a/core/modules/syslog/syslog.module b/core/modules/syslog/syslog.module
index 1327606..e138656 100644
--- a/core/modules/syslog/syslog.module
+++ b/core/modules/syslog/syslog.module
@@ -45,18 +45,19 @@ function syslog_help($path, $arg) {
  * Implements hook_form_FORM_ID_alter().
  */
 function syslog_form_system_logging_settings_alter(&$form, &$form_state) {
+  $config = config('syslog.settings');
   $help = module_exists('help') ? ' ' . l(t('More information'), 'admin/help/syslog') . '.' : NULL;
   $form['syslog_identity'] = array(
     '#type'          => 'textfield',
     '#title'         => t('Syslog identity'),
-    '#default_value' => variable_get('syslog_identity', 'drupal'),
+    '#default_value' => $config->get('identity'),
     '#description'   => t('A string that will be prepended to every message logged to Syslog. If you have multiple sites logging to the same Syslog log file, a unique identity per site makes it easy to tell the log entries apart.') . $help,
   );
   if (defined('LOG_LOCAL0')) {
     $form['syslog_facility'] = array(
       '#type'          => 'select',
       '#title'         => t('Syslog facility'),
-      '#default_value' => variable_get('syslog_facility', LOG_LOCAL0),
+      '#default_value' => $config->get('facility'),
       '#options'       => syslog_facility_list(),
       '#description'   => t('Depending on the system configuration, Syslog and other logging tools use this code to identify or filter messages from within the entire system log.') . $help,
      );
@@ -64,10 +65,24 @@ function syslog_form_system_logging_settings_alter(&$form, &$form_state) {
   $form['syslog_format'] = array(
     '#type'          => 'textarea',
     '#title'         => t('Syslog format'),
-    '#default_value' => variable_get('syslog_format', '!base_url|!timestamp|!type|!ip|!request_uri|!referer|!uid|!link|!message'),
+    '#default_value' => $config->get('format'),
     '#description'   => t('Specify the format of the syslog entry. Available variables are: <dl><dt><code>!base_url</code></dt><dd>Base URL of the site.</dd><dt><code>!timestamp</code></dt><dd>Unix timestamp of the log entry.</dd><dt><code>!type</code></dt><dd>The category to which this message belongs.</dd><dt><code>!ip</code></dt><dd>IP address of the user triggering the message.</dd><dt><code>!request_uri</code></dt><dd>The requested URI.</dd><dt><code>!referer</code></dt><dd>HTTP Referer if available.</dd><dt><code>!uid</code></dt><dd>User ID.</dd><dt><code>!link</code></dt><dd>A link to associate with the message.</dd><dt><code>!message</code></dt><dd>The message to store in the log.</dd></dl>'),
   );
-  $form['actions']['#weight'] = 1;
+
+  $form['#submit'][] = 'syslog_logging_settings_submit';
+}
+
+/**
+ * Form submission handler for system_logging_settings().
+ *
+ * @see syslog_form_system_logging_settings_alter()
+ */
+function syslog_logging_settings_submit($form, &$form_state) {
+  config('syslog.settings')
+    ->set('identity', $form_state['values']['syslog_identity'])
+    ->set('facility', $form_state['values']['syslog_facility'])
+    ->set('format', $form_state['values']['syslog_format'])
+    ->save();
 }
 
  /**
@@ -95,14 +110,18 @@ function syslog_watchdog(array $log_entry) {
   global $base_url;
 
   $log_init = &drupal_static(__FUNCTION__, FALSE);
+  $config = config('syslog.settings');
 
   if (!$log_init) {
     $log_init = TRUE;
-    $default_facility = defined('LOG_LOCAL0') ? LOG_LOCAL0 : LOG_USER;
-    openlog(variable_get('syslog_identity', 'drupal'), LOG_NDELAY, variable_get('syslog_facility', $default_facility));
+    $facility = $config->get('facility');
+    if ($facility === '') {
+      $facility = defined('LOG_LOCAL0') ? LOG_LOCAL0 : LOG_USER;
+    }
+    openlog($config->get('identity'), LOG_NDELAY, $facility);
   }
 
-  $message = strtr(variable_get('syslog_format', '!base_url|!timestamp|!type|!ip|!request_uri|!referer|!uid|!link|!message'), array(
+  $message = strtr($config->get('format'), array(
     '!base_url'    => $base_url,
     '!timestamp'   => $log_entry['timestamp'],
     '!type'        => $log_entry['type'],
diff --git a/core/modules/system/config/system.logging.yml b/core/modules/system/config/system.logging.yml
new file mode 100644
index 0000000..3ecc76c
--- /dev/null
+++ b/core/modules/system/config/system.logging.yml
@@ -0,0 +1 @@
+error_level: all
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
index 90d6229..f80d840 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
@@ -274,7 +274,7 @@ class RenderTest extends WebTestBase {
     );
     $message = t('%type: !message in %function (line ', $error);
 
-    variable_set('error_level', ERROR_REPORTING_DISPLAY_ALL);
+    config('system.logging')->set('error_level', ERROR_REPORTING_DISPLAY_ALL)->save();
     $this->drupalGet('common-test/drupal-render-invalid-keys');
     $this->assertResponse(200, t('Received expected HTTP status code.'));
     $this->assertRaw($message, t('Found error message: !message.', array('!message' => $message)));
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/ErrorHandlerTest.php b/core/modules/system/lib/Drupal/system/Tests/System/ErrorHandlerTest.php
index 0d40b08..b225aed 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/ErrorHandlerTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/ErrorHandlerTest.php
@@ -29,6 +29,7 @@ class ErrorHandlerTest extends WebTestBase {
    * Test the error handler.
    */
   function testErrorHandler() {
+    $config = config('system.logging');
     $error_notice = array(
       '%type' => 'Notice',
       '!message' => 'Undefined variable: bananas',
@@ -49,7 +50,7 @@ class ErrorHandlerTest extends WebTestBase {
     );
 
     // Set error reporting to collect notices.
-    variable_set('error_level', ERROR_REPORTING_DISPLAY_ALL);
+    $config->set('error_level', ERROR_REPORTING_DISPLAY_ALL)->save();
     $this->drupalGet('error-test/generate-warnings');
     $this->assertResponse(200, t('Received expected HTTP status code.'));
     $this->assertErrorMessage($error_notice);
@@ -57,7 +58,7 @@ class ErrorHandlerTest extends WebTestBase {
     $this->assertErrorMessage($error_user_notice);
 
     // Set error reporting to not collect notices.
-    variable_set('error_level', ERROR_REPORTING_DISPLAY_SOME);
+    $config->set('error_level', ERROR_REPORTING_DISPLAY_SOME)->save();
     $this->drupalGet('error-test/generate-warnings');
     $this->assertResponse(200, t('Received expected HTTP status code.'));
     $this->assertNoErrorMessage($error_notice);
@@ -65,7 +66,7 @@ class ErrorHandlerTest extends WebTestBase {
     $this->assertErrorMessage($error_user_notice);
 
     // Set error reporting to not show any errors.
-    variable_set('error_level', ERROR_REPORTING_HIDE);
+    $config->set('error_level', ERROR_REPORTING_HIDE)->save();
     $this->drupalGet('error-test/generate-warnings');
     $this->assertResponse(200, t('Received expected HTTP status code.'));
     $this->assertNoErrorMessage($error_notice);
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index d956f05..c8f1829 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -1646,13 +1646,13 @@ function system_run_cron_submit($form, &$form_state) {
  * Form builder; Configure error reporting settings.
  *
  * @ingroup forms
- * @see system_settings_form()
+ * @see system_logging_settings_submit()
  */
-function system_logging_settings() {
+function system_logging_settings($form, &$form_state) {
   $form['error_level'] = array(
     '#type' => 'radios',
     '#title' => t('Error messages to display'),
-    '#default_value' => variable_get('error_level', ERROR_REPORTING_DISPLAY_ALL),
+    '#default_value' => config('system.logging')->get('error_level'),
     '#options' => array(
       ERROR_REPORTING_HIDE => t('None'),
       ERROR_REPORTING_DISPLAY_SOME => t('Errors and warnings'),
@@ -1662,7 +1662,18 @@ function system_logging_settings() {
     '#description' => t('It is recommended that sites running on production environments do not display any errors.'),
   );
 
-  return system_settings_form($form);
+  return system_config_form($form, $form_state);
+}
+
+/**
+ * Form submission handler for system_logging_settings().
+ *
+ * @ingroup forms
+ */
+function system_logging_settings_submit($form, &$form_state) {
+  config('system.logging')
+    ->set('error_level', $form_state['values']['error_level'])
+    ->save();
 }
 
 /**
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index 91d5304..c5a6228 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -1972,6 +1972,27 @@ function system_update_8013() {
 }
 
 /**
+ * Moves system logging settings from variables to config.
+ */
+function system_update_8014() {
+  update_variables_to_config('system.logging', array(
+    'error_level' => 'error_level',
+  ));
+  // Update the numeric error_level value to a string identifier.
+  $config = config('system.logging');
+  $map = array(
+    '0' => 'hide',
+    '1' => 'some',
+    '2' => 'all',
+    '3' => 'verbose',
+    // Also map the system.logging:error_level default value.
+    'all' => 'all',
+  );
+  $config->set('error_level', $map[$config->get('error_level')]);
+  $config->save();
+}
+
+/**
  * @} End of "defgroup updates-7.x-to-8.x".
  * The next series of updates should start at 9000.
  */