diff --git a/npm-shrinkwrap.json b/npm-shrinkwrap.json
index f914a6a0b..d2a07a2a5 100644
--- a/npm-shrinkwrap.json
+++ b/npm-shrinkwrap.json
@@ -2030,6 +2030,11 @@
         }
       }
     },
+    "node-df": {
+      "version": "0.1.1",
+      "from": "node-df@*",
+      "resolved": "https://registry.npmjs.org/node-df/-/node-df-0.1.1.tgz"
+    },
     "node-uuid": {
       "version": "1.4.7",
       "from": "https://registry.npmjs.org/node-uuid/-/node-uuid-1.4.7.tgz",
diff --git a/package.json b/package.json
index 458fd88b4..257c89822 100644
--- a/package.json
+++ b/package.json
@@ -42,6 +42,7 @@
     "multiparty": "^4.1.2",
     "mysql": "^2.7.0",
     "native-dns": "^0.7.0",
+    "node-df": "^0.1.1",
     "node-uuid": "^1.4.3",
     "nodemailer": "^1.3.0",
     "nodemailer-smtp-transport": "^1.0.3",
diff --git a/src/cloudron.js b/src/cloudron.js
index e8ce785b2..34a62b30c 100644
--- a/src/cloudron.js
+++ b/src/cloudron.js
@@ -22,6 +22,8 @@ exports = module.exports = {
 
     isConfiguredSync: isConfiguredSync,
 
+    checkDiskSpace: checkDiskSpace,
+
     events: new (require('events').EventEmitter)(),
 
     EVENT_ACTIVATED: 'activated',
@@ -37,8 +39,10 @@ var apps = require('./apps.js'),
     clientdb = require('./clientdb.js'),
     config = require('./config.js'),
     debug = require('debug')('box:cloudron'),
+    df = require('node-df'),
     fs = require('fs'),
     locker = require('./locker.js'),
+    mailer = require('./mailer.js'),
     os = require('os'),
     path = require('path'),
     paths = require('./paths.js'),
@@ -742,3 +746,28 @@ function backupBoxAndApps(callback) {
         });
     });
 }
+
+function checkDiskSpace(callback) {
+    callback = callback || function () { }; // callback can be empty for timer triggered check
+
+    debug('Checking disk space');
+
+    df(function (error, entries) {
+        if (error) {
+            debug('df error %s', error.message);
+            mailer.outOfDiskSpace(error.message);
+            return callback();
+        }
+
+        var oos = entries.some(function (entry) {
+            return (entry.mount === paths.DATA_DIR && entry.capacity >= 0.90) ||
+                   (entry.mount === '/' && entry.capacity >= 0.95);
+        });
+
+        debug('Disk space checked. ok: %s', !oos);
+
+        if (oos) mailer.outOfDiskSpace(JSON.stringify(entries, null, 4));
+
+        callback();
+    });
+}
diff --git a/src/cron.js b/src/cron.js
index 5c44a3f1a..c0c3b0685 100644
--- a/src/cron.js
+++ b/src/cron.js
@@ -25,7 +25,8 @@ var gAutoupdaterJob = null,
     gCleanupTokensJob = null,
     gDockerVolumeCleanerJob = null,
     gSchedulerSyncJob = null,
-    gCertificateRenewJob = null;
+    gCertificateRenewJob = null,
+    gCheckDiskSpaceJob = null;
 
 var NOOP_CALLBACK = function (error) { if (error) console.error(error); };
 
@@ -69,6 +70,14 @@ function recreateJobs(unusedTimeZone, callback) {
             timeZone: allSettings[settings.TIME_ZONE_KEY]
         });
 
+        if (gCheckDiskSpaceJob) gCheckDiskSpaceJob.stop();
+        gCheckDiskSpaceJob = new CronJob({
+            cronTime: '00 30 */4 * * *', // every 4 hours
+            onTick: cloudron.checkDiskSpace,
+            start: true,
+            timeZone: allSettings[settings.TIME_ZONE_KEY]
+        });
+
         if (gBoxUpdateCheckerJob) gBoxUpdateCheckerJob.stop();
         gBoxUpdateCheckerJob = new CronJob({
             cronTime: '00 */10 * * * *', // every 10 minutes
diff --git a/src/mail_templates/out_of_disk_space.ejs b/src/mail_templates/out_of_disk_space.ejs
new file mode 100644
index 000000000..7e2c3d6ec
--- /dev/null
+++ b/src/mail_templates/out_of_disk_space.ejs
@@ -0,0 +1,19 @@
+<%if (format === 'text') { %>
+
+Dear Cloudron Team,
+
+<%= fqdn %> is running out of disk space.
+
+Please see some excerpts of the logs below.
+
+Thank you,
+Your Cloudron
+
+-------------------------------------
+
+<%- message %>
+
+<% } else { %>
+
+<% } %>
+
diff --git a/src/mailer.js b/src/mailer.js
index 9b966adaf..05efc1f34 100644
--- a/src/mailer.js
+++ b/src/mailer.js
@@ -18,6 +18,8 @@ exports = module.exports = {
 
     appDied: appDied,
 
+    outOfDiskSpace: outOfDiskSpace,
+
     FEEDBACK_TYPE_FEEDBACK: 'feedback',
     FEEDBACK_TYPE_TICKET: 'ticket',
     FEEDBACK_TYPE_APP: 'app',
@@ -358,6 +360,19 @@ function appUpdateAvailable(app, updateInfo) {
     });
 }
 
+function outOfDiskSpace(message) {
+    assert.strictEqual(typeof message, 'string');
+
+    var mailOptions = {
+        from: config.get('adminEmail'),
+        to: 'admin@cloudron.io',
+        subject: util.format('[%s] Out of disk space alert', config.fqdn()),
+        text: render('out_of_disk_space.ejs', { fqdn: config.fqdn(), message: message, format: 'text' })
+    };
+
+    sendMails([ mailOptions ]);
+}
+
 // this function bypasses the queue intentionally. it is also expected to work without the mailer module initialized
 // crashnotifier should be able to send mail when there is no db
 function sendCrashNotification(program, context) {