diff --git a/src/routes/cloudron.js b/src/routes/cloudron.js
index a9c3a1a90..4935ae6b1 100644
--- a/src/routes/cloudron.js
+++ b/src/routes/cloudron.js
@@ -175,7 +175,7 @@ async function getDiskUsage(req, res, next) {
     const [error, result] = await safe(system.getDiskUsage());
     if (error) return next(BoxError.toHttpError(error));
 
-    next(new HttpSuccess(201, { usage: result }));
+    next(new HttpSuccess(200, { usage: result }));
 }
 
 async function updateDiskUsage(req, res, next) {
diff --git a/src/routes/test/cloudron-test.js b/src/routes/test/cloudron-test.js
index e13344bb7..e99acf951 100644
--- a/src/routes/test/cloudron-test.js
+++ b/src/routes/test/cloudron-test.js
@@ -14,7 +14,7 @@ const constants = require('../../constants.js'),
     settings = require('../../settings.js');
 
 describe('Cloudron API', function () {
-    const { setup, cleanup, serverUrl, owner, user } = common;
+    const { setup, cleanup, serverUrl, owner, user, waitForTask } = common;
 
     before(setup);
     after(cleanup);
@@ -369,6 +369,46 @@ describe('Cloudron API', function () {
         });
     });
 
+    describe('disks', function () {
+        it('succeeds', async function () {
+            const response = await superagent.get(`${serverUrl}/api/v1/cloudron/disks`)
+                .query({ access_token: owner.token });
+
+            expect(response.statusCode).to.equal(200);
+            expect(response.body.disks).to.be.ok();
+            expect(Object.keys(response.body.disks).some(fs => response.body.disks[fs].mountpoint === '/')).to.be(true);
+        });
+    });
+
+    describe('disk usage', function () {
+        it('get succeeds with no cache', async function () {
+            const response = await superagent.get(`${serverUrl}/api/v1/cloudron/disk_usage`)
+                .query({ access_token: owner.token })
+                .send({});
+
+            expect(response.statusCode).to.equal(200);
+            expect(response.body).to.eql({ usage: null });
+        });
+
+        it('update the cache', async function () {
+            const response = await superagent.post(`${serverUrl}/api/v1/cloudron/disk_usage`)
+                .query({ access_token: owner.token });
+
+            expect(response.statusCode).to.equal(201);
+            expect(response.body.taskId).to.be.ok();
+            await waitForTask(response.body.taskId);
+        });
+
+        it('get succeeds with cache', async function () {
+            const response = await superagent.get(`${serverUrl}/api/v1/cloudron/disk_usage`)
+                .query({ access_token: owner.token })
+                .send({});
+
+            expect(response.statusCode).to.equal(200);
+            console.log(response.body);
+        });
+    });
+
     describe('languages', function () {
         it('succeeds', async function () {
             const response = await superagent.get(`${serverUrl}/api/v1/cloudron/languages`);
diff --git a/src/system.js b/src/system.js
index 956f75037..db8a21f5a 100644
--- a/src/system.js
+++ b/src/system.js
@@ -147,13 +147,12 @@ function getMemoryAllocation(limit) {
     return Math.round(Math.round(limit * ratio) / 1048576) * 1048576; // nearest MB
 }
 
-function getDiskUsage() {
-    const output = safe.JSON.parse(safe.fs.readFileSync(paths.DISK_USAGE_FILE, 'utf8'));
-    return output;
+async function getDiskUsage() {
+    return safe.JSON.parse(safe.fs.readFileSync(paths.DISK_USAGE_FILE, 'utf8'));
 }
 
 async function updateDiskUsage(progressCallback) {
-    assert.strictEqual(progressCallback, 'function');
+    assert.strictEqual(typeof progressCallback, 'function');
 
     const disks = await getDisks();
     const filesystems = Object.keys(disks);
@@ -169,8 +168,8 @@ async function updateDiskUsage(progressCallback) {
 
         for (const content of disk.contents) {
             progressCallback({ message: `Checking du of ${JSON.stringify(content)}`});
-            if (content.type === 'docker') {
-                content.usage = (await docker.du()).LayersSize;
+            if (content.id === 'docker') {
+                content.usage = (await docker.df()).LayersSize;
             } else {
                 content.usage = await du(content.path, { exclude: content.exclude });
             }