diff --git a/clearurls.js b/clearurls.js
index ef07255..a9160ed 100644
--- a/clearurls.js
+++ b/clearurls.js
@@ -308,6 +308,7 @@ function start()
                             else {
                                 toObject(storage.ClearURLsData);
                                 storeHashStatus(1);
+                                saveOnDisk(['hashStatus']);
                             }
                         }
                         else {
@@ -345,6 +346,7 @@ function start()
                             }
                             storage.ClearURLsData = JSON.parse(storage.ClearURLsData);
                             toObject(storage.ClearURLsData);
+                            saveOnDisk(['ClearURLsData', 'dataHash', 'hashStatus']);
                         }
                     });
                 }
@@ -777,5 +779,6 @@ function start()
                     "timestamp": Date.now()
                 }
             );
+            deferSaveOnDisk('log');
         }
     }
diff --git a/core_js/storage.js b/core_js/storage.js
index a036fa2..329f046 100644
--- a/core_js/storage.js
+++ b/core_js/storage.js
@@ -47,13 +47,51 @@ function saveOnExit()
 }
 
 /**
-* Save the value under the key on the disk.
-* @param  {String} key
-* @param  {Object} value
+* Save multiple keys on the disk.
+* @param  {String[]} keys
 */
-function saveOnDisk(key, value)
+function saveOnDisk(keys)
 {
-    browser.storage.local.set({key: value});
+    var json = {};
+
+    keys.forEach(function(key) {
+        var value = storage[key];
+        switch (key) {
+            case "ClearURLsData":
+            case "log":
+            json[key] = JSON.stringify(value);
+            break;
+            case "types":
+            json[key] = value.toString();
+            break;
+            default:
+            json[key] = value;
+        }
+    });
+    console.log(translate('core_save_on_disk'));
+    browser.storage.local.set(json);
+}
+
+var hasPendingSaves = false;
+var pendingSaves = new Set();
+
+/**
+* Schedule to save a key to disk in 30 seconds.
+* @param  {String} key
+*/
+function deferSaveOnDisk(key)
+{
+    if (hasPendingSaves) {
+        pendingSaves.add(key);
+        return;
+    }
+
+    setTimeout(function() {
+        saveOnDisk(Array.from(pendingSaves));
+        pendingSaves.clear();
+        hasPendingSaves = false;
+    }, 30000);
+    hasPendingSaves = true;
 }
 
 /**
@@ -85,6 +123,10 @@ function getEntireData()
 
 /**
 * Save the value under the key on the RAM.
+*
+* Note: To store the data on the hard disk, one of
+*  deferSaveOnDisk(), saveOnDisk(), or saveOnExit()
+*  must be called.
 * @param {String} key
 * @param {Object} value
 */
@@ -199,7 +241,7 @@ function loadOldDataFromStore()
 }
 
 /**
-* Save the hash status to the local storage.
+* Save the hash status to the local storage (RAM).
 * The status can have the following values:
 *  1 "up to date"
 *  2 "updated"
@@ -222,10 +264,5 @@ function storeHashStatus(status_code)
     storage.hashStatus = status_code;
 }
 
-/**
-* Save every minute the temporary data to the disk.
-*/
-setInterval(saveOnExit, 60000);
-
 // Start storage
 getDataFromDisk();
diff --git a/core_js/tools.js b/core_js/tools.js
index aa66cc2..d02aa61 100644
--- a/core_js/tools.js
+++ b/core_js/tools.js
@@ -199,7 +199,7 @@ function loadOldDataFromStore()
 }
 
 /**
-* Save the hash status to the local storage.
+* Save the hash status to the local storage (RAM).
 * The status can have the following values:
 *  1 "up to date"
 *  2 "updated"
@@ -231,6 +231,7 @@ function increaseGlobalURLCounter(number)
     if(storage.statisticsStatus)
     {
         storage.globalurlcounter += number;
+        deferSaveOnDisk('globalurlcounter');
     }
 }
 
@@ -242,6 +243,7 @@ function increaseURLCounter()
     if(storage.statisticsStatus)
     {
         storage.globalCounter++;
+        deferSaveOnDisk('globalCounter');
     }
 }