Quickstart Guide for Duplicati and Backblaze B2 Cloud Storage Quickstart Guide for Duplicati and Backblaze B2 Cloud Storage

Quickstart Guide for Duplicati and Backblaze B2 Cloud Storage

Udara Gunawardena Udara Gunawardena


Duplicati is a free, open-source backup program that runs on Windows, macOS, and Linux.  Duplicati comes with a web interface for management and works with standard protocols like FTP, SSH, WebDAV as well as cloud storage providers like Backblaze B2.


The newest version is 2.0 (beta).


You can download Duplicati for your operating system at the link below.  Look for the word “beta” in the release name.  




In this example, we are installing Duplicati on Windows.


Setup Guide

1. Run the installer, accepting the default settings, and launch Duplicati when done


Even if you don’t want to set a password for Duplicati, click Yes, as this will take us to the settings page where we can make some adjustments.



2. At the top of the Settings page, you can enter a password if you like and review other options that you may want to set



At the bottom of the Settings page, we can change some default options that will improve the performance of backing up to Backblaze B2




3. The first option we want to configure is asynchronous-concurrent-upload-limit


The default value is 4, but increasing this value will improve your transfer speed, by increasing the number of files that can be uploaded at the same time


You will want to test this in your environment, but we suggest starting with a value of 10. Results depend on available bandwidth and client CPU strength




4. The second option we want to configure is concurrency-max-threads

Adjusting this setting controls how many CPU threads to use for checking and compressing the backups.  The default value of 0 should dynamically balance the number of threads based on your hardware.


If you have current processors, try increasing this value and comparing your backup times




5. Increasing the number-of-retries will help Duplicati overcome temporary issues encountered over the internet during the file transfer 


A value of 15 allows more time and opportunity for the transfer to succeed instead of failing




Backup Configuration


1. Add a new backup by clicking Add backup from the navigation menu

Currently, Duplicati lacks the concept of defined Cloud Destinations. Thus for every backup source, you have to enter your cloud credentials again for the destination




2. Enter a description for this backup, and optionally encrypt it with a passphrase, and click Next

Be sure to store your passphrase in a password vault for easy recovery.

Change the Encryption field to no encryption if you would like to bypass backup encryption. 



3. Configure your backup destination.  In the Storage Type field, select B2 Cloud Storage, then enter a bucket name and optional folder under the bucket to store this backup.


Enter your Backblaze B2 Key Id and Application Key into the appropriate fields, and click Test connection to verify the credentials worked.  If the bucket you entered does not exist in your account yet, you will be prompted to create the bucket.



4. Select the source data for your backup.  It can be an individual project folder, your drive, etc. You can also use Filters and Exclude rules to customize your backups further


Click Next when you have selected all the files to be included in this backup



5. Define your backup schedule, and then click Next for more options




6. Duplicati backups are processed into “volumes” or backup chunks, these chunks of the backup are transmitted to your backup storage. For the Remote volume size, the default value of 50 MB is a friendly size for users with slow upload speeds. Set the remote volume size to 100 MB if you have a faster upload connection.


For Backup retention, we recommend choosing the Smart backup retention option.  As it describes it will keep weekly, monthly, and yearly backups for you, and purge the rest.  You can review the other options if you have other backup needs.  When you are done click Save and you're finished.



7. You can review the status of your backups, review logs, restore files, etc., by picking your backup from the list on the Home screen. After your first backup, you can see how much compression Duplicati was able to achieve by comparing the Source to the Backup size.