No data but appears to backup

Duplicati appears to backup but no data actually makes it to the endpoint.


  • NGINX Reverse Proxy (SSL’d) -
  • Minio S3 -
  • Duplicati client (macbook) - remote

I am able to upload files to the relevant bucket through Minio’s web interface. Duplicati acts like it is moving data onto the S3 server - the gigabytes to go consistently gets lower. Once it gets all the way down, it hangs on verification - likely because there is no data to verify!

NGINX Config (with Let’s Encrypt stuff and URLs redacted):

server {

server_name url.url;

location / {
proxy_set_header Host $http_host;
proxy_buffering off;
client_max_body_size 0;

My guess is that the backups are happening but to a different folder than expected.

A few ways to check this include:

  • If you monitor your bandwidth while a backup is running do you see any traffic?
  • If you get a job summary email (or even in the “Results” block in the job Log menu item) do you see any values for things like “AddedFiles” or “ModifiedFiles”?
    DeletedFiles: 57 
    DeletedFolders: 1 
    ModifiedFiles: 181 
    ExaminedFiles: 3791 
    OpenedFiles: 487 
    AddedFiles: 306 
  • If you go to the job Log page and click on the “Remote” tab do you see any "put duplicati-xxxxxx" type messages?

  • Can you check the before / after free space sizes on your destination?

It looks like Duplicati acts like it is sending data, but it looks like no data is sent.

Edit: I verified NGINX is not at issue. I VPN’d in and used the local Problem still exists. No data shows in Activity Monitor and Duplicati behaves the same.

edit2: Duplicati acts likes its backing up even before the wifi has connected!

edit3: I never installed Mono. I bet that’s the issue. I didn’t realize it has to be installed separately.

edit4: Installed Mono. Identical error now. Rebooted Mac to make sure. “mono-sgen-64” has sent around 1MB, but Duplicati has “sent” well over a gigabyte. Minio web interface still shows the bucket as empty.

edit5: Confirmed working with Cloudberry. Nevertheless I want to use Duplicati if at all possible. I want free software to encourage friends and family to backup. If they have to pay anything, they won’t :frowning:

Wow I’m really confused - @Pectojin would know better, but I’m pretty sure you wouldn’t have gotten even the GUI interface to come on MacOS up if you didn’t already mono installed…

Have you tried a test restore yet? If nothing is being backed up, then a restore should fail.

Also, can you share your job configuration? Try the job “Export” menu and select “As Commandline…” then copy / paste that here (with person stuff like passwords and email addresses removed.

Well, I assumed I didn’t have Mono installed because it isn’t in my Applications folder. But it still isn’t, so it must install somewhere else. I probably already had it installed. I’ll get what you asked for soon. Thank you for your help. It means a lot.