There are several entry points available for administrator to manage the configuration of Rdiffweb. This section aims to outline those configurations and explain each option available and what it does.

Since version 2.2, rdiffweb configuration is more flexible. You may configure every option using the configuration file, command line argument or environment variable.

Take note that configuration options are distinct from the runtime setting, available from the web interface. The configuration options here usually meant to be static and set before starting the server. You may get the list of configuration options by calling rdiffweb --help.

Note: If an option is specified in more than one place, the command line arguments override the environment variable, environment variables override config files, and config files override default value.

Configuration file

To use configuration files, you may call rdiffweb with -f or --config to define the configuration file location. When not defined, Rdiffweb loads all configuration files from these locations by default:

  • /etc/rdiffweb/rdw.conf

  • /etc/rdiffweb/rdw.conf.d/*.conf

Configuration file syntax must define a key and a value. The key is case-sensitive, and you may use underscore (_) or dash (-) seemlessly. All lines beginning with ‘#’ are comments and are intended for you to read. All other lines are configuration for rdiffweb.


# This is a comment

Environment variables

In addition to configuration files, you may pass environment variables. The options name must be uppercase and prefixed with RDIFFWEB_. As an example, if you want to change the port used to listen for HTTP request for 8081, you must define server-port option as follow.


Command line arguments

When launching rdiffweb executable, you may pass as many arguments as you want on the command line. The options must be prefixed with double dash (--) and you must single dash (-) to separate words.

E.g. --server-port 8081 or --server-port=8081 are valid

Configure listening port and interface

For security reasons, Rdiffweb listen on port 8080 for HTTP request on loopback interface ( by default. Consider configuring a reverse proxy like Nginx or Apache2 if you want to make Rdiffweb listen on port 80 for HTTP and port 443 for HTTPS request.

Option Description Example
server-host Define the IP address to listen to. Use to listen on all interfaces. Use to listen on loopback interface.
server-port Define the port to listen for HTTP request. Default to 8080 9090

Configure administrator username & password

Using configuration file, you may setup a special administrator which cannot be deleted or renamed from the web interface. You may also configure a specific password for this user that cannot be updated from the web interface either.

In addition, you may also create other administrator users to manage Rdiffweb.

Parameter Description Example
admin-user Define the name of the default admin user to be created admin
admin-password administrator encrypted password as SSHA. Read online documentation to know more about how to encrypt your password into SSHA or use When defined, administrator password cannot be updated using the web interface. When undefined, default administrator password is admin123 and it can be updated using the web interface. modification

Configure logging

Rdiffweb can be configured to send logs to specific location. By default, logs are sent to the console (stdout or stderr). If you have installed Rdiffweb on a server, you should consider enabling the logging to help you keep track of the activities or to help you debug problem.

Option Description Example
log-level Define the log level. ERROR, WARN, INFO, DEBUG DEBUG
log-file Define the location of the log file. /var/log/rdiffweb/server.log
log-access-file Define the location of the access log file. /var/log/rdiffweb/access.log

Enable Debugging log

A specific option is also available if you want to enable the debugging log. We do not recommend to enable this option in production as it may leak information to the user whenever an exception is raised.

Option Description Example
debug enable rdiffweb debug mode - change the log level to DEBUG, print exception stack trace to the web interface and show SQL query in logs.
environment Define the type of environment: development or production. This is used to limit the information shown to the user when an error occurs. Default: production development

Configure database

Rdiffweb use SQL database to store user preferences. The embedded SQLite database is well suited for small deployment (1-100 users). If you intended to have a large deployment, you must consider using a PostgreSQL database instead.

Option Description Example
database-uri Location of the database used for persistence. SQLite and PostgreSQL database are supported officially. To use a SQLite database, you may define the location using a file path or a URI. e.g.: /srv/rdiffweb/file.db or sqlite:///srv/rdiffweb/file.db. To use PostgreSQL server, you must provide a URI similar to postgresql://user:pass@ and you must install required dependencies. By default, Rdiffweb uses a SQLite embedded database located at /etc/rdiffweb/rdw.db. postgresql://user:pass@


To use embedded SQLite database, pass the option database-uri with a URI similar to sqlite:///etc/rdiffweb/rdw.db or /etc/rdiffweb/rdw.db.


To use an external PostgreSQL database, pass the option database-uri with a URI similar to postgresql://user:pass@

You may need to install additional dependencies to connect to PostgreSQL. Step to install dependencies might differ according to the way you installed Rdiffweb.

Using Debian repository:

apt install python3-psycopg2

Using Pypi repository:

pip install psycopg2-binary

Configure LDAP Authentication

Rdiffweb may integrates with LDAP server to support user authentication.

This integration works with most LDAP-compliant servers, including:

  • Microsoft Active Directory

  • Apple Open Directory

  • Open LDAP

  • 389 Server

LDAP options

Option Description Example
ldap-add-missing-user True to create users from LDAP when the credential is valid. True
ldap-add-user-default-role Role to be used when creating a new user from LDAP. Default: user maintainer
ldap-add-user-default-userroot Userroot to be used when creating a new user from LDAP. Default: empty /backups/{cn[0]}
ldap-allow-password-change true to allow LDAP users to update their password using rdiffweb. This option should only be enabled if the LDAP if confiugred to allow the user to change their own password. Default to false. true
ldap-base-dn The DN of the branch of the directory where all searches should start from. dc=my,dc=domain
ldap-bind-dn An optional DN used to bind to the server when searching for entries. If not provided, will use an anonymous bind. cn=manager,dc=my,dc=domain
ldap-bind-password A bind password to use in conjunction with LdapBindDn. Note that the bind password is probably sensitive data,and should be properly protected. You should only use the LdapBindDn and LdapBindPassword if you absolutely need them to search the directory. mypassword
ldap-check-shadow-expire enable validation of shadow expired when validating user's credential. User will not be allowed to login if the account expired. true
ldap-encoding encoding used by your LDAP server. Default to utf-8 cp1252
ldap-filter A valid LDAP search filter. If not provided, defaults to (objectClass=*), which will search for all objects in the tree. (objectClass=*)
ldap-group-attribute-is-dn True if the content of the attribute ldap-group-attribute is a DN. true
ldap-group-attribute name of the attribute defining the groups of which the user is a member. Should be used with ldap-required-group and ldap-group-attribute-is-dn. member
ldap-network-timeout Optional timeout value. Default to 10 sec. 10
ldap-protocol-version Version of LDAP in use either 2 or 3. Default to 3. 3
ldap-required-group name of the group of which the user must be a member to access rdiffweb. Should be used with ldap-group-attribute and ldap-group-attribute-is-dn. rdiffweb
ldap-scope The scope of the search. Can be either base, onelevel or subtree. Default to subtree. onelevel
ldap-timeout Optional timeout value. Default to 300 sec. 300
ldap-tls true to enable TLS. Default to false false
ldap-uri URIs containing only the schema, the host, and the port. ldap://localhost:389
ldap-username-attribute The attribute to search username. If no attributes are provided, the default is to use uid. It's a good idea to choose an attribute that will be unique across all entries in the subtree you will be using. cn
ldap-version version of LDAP in use either 2 or 3. Default to 3. 3

Automatically create user in Rdiffweb

If you have a large number of users in your LDAP, you may want to configure Rdiffweb to automatically create user in database that has valid LDAP credentials. The user will get created on first valid login.

You may optionally pass other options like ldap-add-user-default-role and ldap-add-user-default-userroot to automatically define the default user role and default user root for any new user created from LDAP.

Here a working configuration:


Restrict access to a specific LDAP group

If you are making use of LDAP credentials validation, you will usually want to limit the access to member of a specific LDAP group. Rdiffweb support such scenario with the use of ldap-required-group, ldap-group-attribute and ldap-group-attribute-is-dn.

Here is an example of how you may limit Rdiffweb access to members of Admin_Backup group. This configuration is known to work with LDAP PosixAccount and PosixGroup.


Configure email notifications

Since Rdiffweb v0.9, you may configure Rdiffweb to send an email notification to the users when their backups did not complete successfully for a period of time. When enabled, Rdiffweb will also send email notification for security reason when user’s password is changed.

Option Description Example
email-encryption Type of encryption to be used when establishing communication with SMTP server. Available values: none, ssl and starttls starttls
email-host SMTP server used to send email.
email-sender email addres used for the From: field when sending email. Rdiffweb
email-notification-time time when the email notification should be sent for inactive backups. 22:00
email-username username used for authentication with the SMTP server.
email-password password used for authentication with the SMTP server. CHANGEME
email-send-changed-notification True to send notification when sensitive information get change in user profile. Default: false True

To configure the notification, you need a valid SMTP server. In this example, you are making use of a Gmail account to send emails.

Note: notifications are not sent if the user doesn’t have an email configured in his profile.

Configure user quota

Since v2.1, it’s now possible to customize how user quota is controller for your system without a custom plugin. By defining quota-set-cmd, quota-get-cmd and QuotaUsedCmd configuration options, you have all the flexibility to manage the quota the way you want by providing custom command line to be executed to respectively set the quota, get the quota and get quota usage.

Option Description Example
quota-set-cmd Command line to set the user's quota. Yes. If you want to allow administrators to set quota from the web interface.
quota-get-cmd Command line to get the user's quota. Should print the size in bytes to console. No. Default behaviour gets quota using operating system statvfs that should be good if you are using setquota, getquota, etc. For ZFS and other more exotic file system, you may need to define this command.
quota-used-cmd Command line to get the quota usage. Should print the size in bytes to console. No.

When Rdiffweb calls the scripts, special environment variables are available. You should make use of this variables in a custom script to get and set the disk quota.

  • RDIFFWEB_USERID: rdiffweb user id. e.g.: 34

  • RDIFFWEB_USERNAME: rdiffweb username. e.g.: patrik

  • RDIFFWEB_USERROOT: user’s root directory. e.g.: /backups/patrik/

  • RDIFFWEB_ROLE: user’s role e.g.: 10 1:Admin, 5:Maintainer, 10:User

  • RDIFFWEB_QUOTA: only available for quota-set-cmd. Define the new quota value in bytes. e.g.: 549755813888 (0.5 TiB)

Continue reading about how to configure quotas for EXT4. We generally recommend making use of project quotas with Rdiffweb to simplify the management of permission and avoid running Rdiffweb with root privileges. The next section presents how to configure project quota. Keep in mind it’s also possible to configure quota using either user’s quota or project quota.

Configure user quota for EXT4

This section is not a full documentation about how to configure ext4 project quota, but provide enough guidance to help you.

  1. Enabled project quota feature
    You must enable project quota feature for the EXT4 partition where your backup resides using:
    tune2fs -O project -Q prjquota /dev/sdaX
    The file system must be unmounted to change this setting and may require you to boot your system with a live-cd if your backups reside on root file system (/).
    Also, add prjquota options to your mount point configuration /etc/fstab. Something like /dev/sdaX   /   ext4    errors=remount-ro,prjquota     0    1

  2. Turn on the project quota after reboot
    quotaon -Pv -F vfsv1 /

  3. Check if the quota is working
    repquota -Ps /

  4. Add +P attribute on directory you which to control quota
    chattr -R +P /backups/admin

  5. Then set the project id on directories
    chattr -R -p 1 /backups/admin where 1 is the rdiffweb user’s id

Next, you may configure Rdiffweb quota command line for your need. For EXT4 project quotas, you only need to define quota-set-cmd with something similar to the following. quota-get-cmd and quota-used-cmd should not be required with EXT4 quota management.

quota-set-cmd=setquota -P $RDIFFWEB_USERID $((RDIFFWEB_QUOTA / 1024)) $((RDIFFWEB_QUOTA / 1024)) 0 0 /

This effectively, makes use of Rdiffweb user’s id as project id.

Configure user quota for ZFS

This section is not a full documentation about how to configure ZFS project quotas, but provide enough guidance to help you. This documentation uses tank/backups as the dataset to store rdiffweb backups.

  1. Quota feature is a relatively new feature for ZFS On Linux. Check your operating system to verify if your ZFS version support it. You may need to upgrade your pool and dataset using:

    zpool upgrade tank zfs upgrade tank/backups

  2. Add +P attribute on directory you which to control quota
    chattr -R +P /backups/admin chattr -R -p 1 /backups/admin OR zfs project -p 1 -rs /backups/admin Where 1 is the rdiffweb user’s id

Take note, it’s better to enable project quota attributes when the repositories are empty.

Configure user’s session persistence.

Rdiffweb could be configured to persist the user’s session information either in memory or on disk. When the user’s session persists in memory, all user’s session get reset if the web server restart. If you want to persist the user’s session even if the web server gets restarted, you may persist them on disk with session-dir option.

Option Description Example
session-dir location where to store user session information. When undefined, the user sessions are kept in memory. /var/run/rdiffweb/sessions

Configure Rdiffweb appearance

A number of options are available to customize the appearance of Rdiffweb to your need. Most likely, you will want to make it closer to your business brand.

Option Description Example
header-name Define the application name displayed in the title bar and header menu. My Backup
default-theme Define the theme. Either: default or orange. Define the css file to be loaded in the web interface. You may manually edit a CSS file to customize it. The location is similar to /usr/local/lib/python2.7/dist-packages/rdiffweb/static/. orange
welcome-msg Replace the headline displayed in the login page. It may contains HTML. Custom message displayed on login page.
favicon Define the FavIcon to be displayed in the browser title /etc/rdiffweb/my-fav.ico

Configure SSH Key management

Rdiffweb allows users to manage their SSH Keys by adding and removing them using the web interface. This feature may be disabled with disable-ssh-keys.

When this feature is enabled, adding or removing an SSH Key from the web interface. Updates, the ${user_root}/.ssh/authorized_keys file if the file already exists.

Configure repositories clean-up job

Using the web interface, users may configure a retention period on individual repository to keep only a fixed number of days in backup. This is useful to control the growth of a repository disk usage.

To support this feature, Rdiffweb schedule a job to clean-up the repositories in backup. This job is ran once a day. You may change the default time when this schedule job is running by defining another value for option remove-older-time.

| Parameter | Description | Example | | — | — | — | — | | remove-older-time | Time when to execute the remove older task | 22:00 |

Configure temporary folder location

To restore file or folder, Rdiffweb needs a temporary directory to create the file to be downloaded. By default, Rdiffweb will use your default temporary folder defined using environment variable TMPDIR, TEMP or TMP. If none of these environment variables are defined, Rdiffweb fallback to use /tmp.

If you want to enforce a different location for the temporary directory, you may define the option tempdir with a different value. Take note, this directory must be created with the right ownership and permissions to allow Rdiffweb to use it. Also make sure enough disk space is available. Usually, a 32GiB is enough.

| Parameter | Description | Example | | — | — | — | — | | tempdir | alternate temporary folder to be used when restoring files. Might be useful if the default location has limited disk space| /tmp/rdiffweb/ |

Configure repository lookup depthness.

When defining the UserRoot value for a user, Rdiffweb will scan the content of this directory recursively to lookups for rdiff-backup repositories. For performance reason, Rdiffweb limits the recursiveness to 5 subdirectories. This default value should suit most use cases. If you have a particular use case, it’s possible to allow Rdiffweb to scan for more subdirectories by defining a greater value for the option max-depth. Make sure to pick a reasonable value for your use case as it may impact the performance.

Parameter Description Example
--max-depth Define the maximum folder depthness to search into the user's root directory to find repositories. This is commonly used if your repositories are organised with multiple sub-folders. Default: 5 No