Tag: backup

  • Backup Your Home Server with Duplicati

    (Note: this is part of my ongoing series on cheaply selfhosting)

    Through some readily available Docker containers and OpenMediaVault, I have a cheap mini-PC which serves as:

    But, over time, as the server has picked up more uses, it’s also become a vulnerability. If any of the drives on my machine ever fail, I’ll lose data that is personally (and sometimes economically) significant.

    I needed a home server backup plan.


    Duplicati is open source software that helps you efficiently and securely backup specific partitions and folders to any destination. This could be another home server or it can be a cloud service provider (like Amazon S3 or Backblaze B2 or even a consumer service like Dropbox, Google Drive, and OneDrive). While there are many other tools that can support backup, I went with Duplicati because I wanted:

    • Support for consumer storage services as a target: I am a customer of Google Drive (through Google One) and Microsoft 365 (which comes with generous OneDrive subscription) and only intend to backup some of the files I’m currently storing (mainly some of the network storage I’m using to hold important files)
    • A web-based control interface so I could access this from any computer (and not just whichever machine had the software I wanted)
    • An active user form so I could find how-to guides and potentially get help
    • Available as a Docker container on linuxserver.io: linuxserver.io is well-known for hosting and maintaining high quality and up-to-date Docker container images


    To install Duplicati on OpenMediaVault:

    • If you haven’t already, make sure you have OMV Extras and Docker Compose installed (refer to the section Docker and OMV-Extras in my previous post, you’ll want to follow all 10 steps as I refer to different parts of the process throughout this post) and have a static local IP address assigned to your server.
    • Login to your OpenMediaVault web admin panel, and then go to [Services > Compose > Files] in the sidebar. Press the button in the main interface to add a new Docker compose file.

      Under Name put down Duplicati and under File, adapt the following (making sure the number of spaces are consistent)
      image: lscr.io/linuxserver/duplicati:latest
      container_name: duplicati
      - <unused port number>:8200
      - TZ: 'America/Los_Angeles'
      - PUID=<UID of Docker User>
      - PGID=<GID of Docker User>
      - <absolute paths to folders to backup>:<names to use in Duplicati interface>
      - <absolute path to shared config folder>/Duplicati:/config
      restart: unless-stopped
      Under ports:, make sure to add an unused port number (I went with 8200).

      Replace <absolute path to shared config folder> with the absolute path to the config folder where you want Docker-installed applications to store their configuration information (accessible by going to [Storage > Shared Folders] in the administrative panel).

      You’ll notice there’s extra lines under volumes: for <absolute paths to folders to backup>. This should correspond with the folders you are interested in backing up. You should map them to names that will show up in the Duplicati interface that you recognize. For example, I directed my <absolute path to shared config folder> to /containerconfigs as one of the things I want to make sure I backup are my containers.

      Once you’re done, hit Save and you should be returned to your list of Docker compose files for the next step. Notice that the new Duplicati entry you created has a Down status, showing the container has yet to be initialized.
    • To start your Duplicati container, click on the new Duplicati entry and press the (up) button. This will create the container, download any files needed, and run it.

      To show it worked, go to your-servers-static-ip-address:8200 from a browser that’s on the same network as your server (replacing 8200 if you picked a different port in the configuration file above) and you should see the Duplicati web interface which should look something like below
    • You can skip this step if you didn’t set up Pihole and local DNS / Nginx proxy or if you don’t care about having a user-readable domain name for Duplicati. But, assuming you do and you followed my instructions, open up WeTTy (which you can do by going to wetty.home in your browser if you followed my instructions or by going to [Services > WeTTY] from OpenMediaVault administrative panel and pressing Open UI button in the main panel) and login as the root user. Run:
      cd /etc/nginx/conf.d
      Pick out the file you created before for your domains and run
      nano <your file name>.conf
      This opens up the text editor nano with the file you just listed. Use your cursor to go to the very bottom of the file and add the following lines (making sure to use tabs and end each line with a semicolon)
      server {
      listen 80;
      server_name <duplicati.home or the domain you'd like to use>;
      location / {
      proxy_pass http://<your-server-static-ip>:<duplicati port no.>;
      And then hit Ctrl+X to exit, Y to save, and Enter to overwrite the existing file. Then in the command line run the following to restart Nginx with your new configuration loaded.
      systemctl restart nginx
      Now, if your server sees a request for duplicati.home (or whichever domain you picked), it will direct them to Duplicati.

      Login to your Pihole administrative console (you can just go to pi.hole in a browser) and click on [Local DNS > DNS Records] from the sidebar. Under the section called Add a new domain/IP combination, fill out under Domain: the domain you just added above (i.e. duplicati.home) and next to IP Address: you should add your server’s static IP address. Press the Add button and it will show up below.

      To make sure it all works, enter the domain you just added (duplicati.home if you went with my default) in a browser and you should see the Duplicati interface!

    Configuring your Backups

    Duplicati conceives of each “backup” as a “source” (folder of files to backup), a “destination” (the place the files should be backed up to), a schedule (how often does the backup run), and some options to configure how the backup works.

    To configure a “backup”, click on +Add Backup button on the menu on the lefthand side. I’ll show you the screens I went through to backup my Docker container configurations:

    1. Add a name (I called it DockerConfigs) and enter a Passphrase (you can use the Generate link to create a strong password) which you’d use to restore from backup. Then hit Next
    2. Enter a destination. Here, you can select another computer or folder connected to your network. You can also select an online storage service.

      I’m using Microsoft OneDrive — for a different service, a quick Google search or a search of the Duplicati how-to forum can give you more specific instructions, but the basic steps of generating an AuthID link appear to be similar across many services.

      I selected Microsoft OneDrive v2 and picked a path in my OneDrive for the backup to go to (Backup/dockerconfigs). I then clicked on the AuthID link and went through an authentication process to formally grant Duplicati access to OneDrive. Depending on the service, you may need to manually copy a long string of letters and numbers and colons into the text field. After all of that, to prove it all worked, press Test connection!

      Then hit Next
    3. Select the source. Use the folder browsing widget on the interface to select the folder you wish to backup.

      If you recall in my configuration step, I mapped the <absolute path to shared config folder> to /containerconfigs which is why I selected this as a one-click way to backup all my Docker container configurations. If necessary, feel free to shut down and delete your current container and start over with a configuration where you point and map the folders in a better way.

      Then hit Next
    4. Pick a schedule. Do you want to backup every day? Once a week? Twice a week? Since my docker container configurations don’t change that frequently, I decided to schedule weekly backups on Saturday early morning (so it wouldn’t interfere with something else I might be doing).

      Pick your option and then hit Next
    5. Select your backup options. Unless you have a strong reason to, I would not change the remote volume size from the default (50 MB). The backup retention, however, is something you may want to think about. Duplicati gives you the option to hold on to every backup (something I would not do unless you have a massive amount of storage relative to the amount of data you want to backup), to hold on to backups younger than a certain age, to hold on to a specific number of backups, or customized permutations of the above.

      The option you should choose depends on your circumstances, but to share what I did. For some of my most important files, I’m using Duplicati’s smart backup retention option (which gives me one backup from the last week, one for each of the last 4 weeks, and one for each of the last 12 months). For some of my less important files (for example, my docker container configurations), I’m holding on to just the last 2 weeks worth of backups.

      Then hit Save and you’re set!

    I hope this helps you on your self-hosted backup journey.

    If you’re interested in how to setup a home server on OpenMediaVault or how to self-host different services, check out all my posts on the subject!