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Configuring Rsync Tasks

8 minute read.

Last Modified 2024-04-18 09:01 EDT

You often need to copy data to another system for backup or when migrating to a new system. A fast and secure way of doing this is by using rsync with SSH.

Rsync provides the ability to either push or pull data. The Push function copies data from TrueNAS to a remote system. The Pull function moves or copies data from a remote system and stores it in the defined Path on the TrueNAS host system.

Before You Begin

There are two ways to connect to a remote system and run an rsyc task: setting up an SSH connection or an rsync module. You need to have either an SSH connection for the remote server already configured or an rsync module configured in a remote rsync server. Each has different preparation requirements.

Preparing SSH Mode Remote Sync

When the remote system is another TrueNAS, set the Rsync Mode to SSH, verify the SSH service is active on both systems, and ensure SSH keys are exchanged between systems. When the remote system is not TrueNAS, make sure that system has the rsync service activated and permissions configured for the user account name that TrueNAS uses to run the rsync task.

Create an SSH connection and keypair. Go to Credentials > Backup Credentials to add an SSH connection and keypair. Download the keys. Enter the admin user that should set up and have permission to perform the remote sync operation with the remote system. If using two TrueNAS systems with the admin user, enter admin. If one system only uses the root user, enter root.
Update the admin user by adding the private key to user in the UI and then adding the private key to the home directory for the admin user. When the Rsync Mode is SSH,
Start the SSH service on both systems. Go to System Settings > Services and enable SSH.

Preparing Module Mode Remote Sync

Create a dataset on the remote TrueNAS (or other system). Write down the host and path to the data on the remote system you plan to sync with.
Create a module on the remote system. On TrueNAS, install an rsync app (for example, Rsyncd) and configure the module.

Creating an SSH Mode Rsync Task

First, enable SSH and establish a connection to the remote server.

Establishing an SSH Connection

Enable SSH on the remote system.

Enable SSH in TrueNAS. Go to System > Services and toggle SSH on.

Set up an SSH connection to the remote server. To do this go to Credentials > Backup Credentials and use SSH Connections and SSH Keypairs. See Adding SSH connections for more information.

Populate the SSH Connections configuration fields as follows:

Semi-Automatic (TrueNAS to TrueNAS)

Select Semi-automatic in Setup Method.
Enter the remote TrueNAS URL.
Fill in the remaining credentials for this TrueNAS to authenticate to the remote TrueNAS and exchange SSH keys.
Select Generate New in Private Key.
Enter a number of seconds for TrueNAS to attempt the connection before timing out and closing the connection.

Manual (TrueNAS to Non-TrueNAS)

Enter the remote host name, port number, and user in the appropriate fields.
Click Discover Remote Host Key to connect to the remote system and automatically populate the Remote Host Key field.
Enter a number of seconds for TrueNAS to attempt the connection before timing out and closing the connection.

After establishing the SSH connection, add the rsync task.

Go to Data Protection and click Add on the Rsync Tasks widget to open the Add Rsync Task screen.

Choose a Direction for the rsync task as either Push or Pull and then define the task Schedule.

Select a User account that matches the SSH connection Username entry in the SSH Connections set up for this remote sync.

Provide a Description for the rsync task.

Select SSH in Rsync Mode. The SSH settings fields show.

Choose a connection method from the Connect using dropdown list.

If selecting SSH private key stored in user’s home directory, enter the IP address or hostname of the remote system in Remote Host. Use the format username@remote_host if the username differs on the remote host. Enter the SSH port number for the remote system in Remote SSH Port. By default, 22 is reserved in TrueNAS.
If selecting SSH connection from the keychain, select an existing SSH connection to a remote system or choose Create New to add a new SSH connection.

Enter a full path to a location on the remote server where you either copy information from or to in Remote Path. Maximum path length is 255 characters.

If the remote path location does not exist, select Validate Remote Path to create and define it in Remote Path.

Select the schedule to use and configure the remaining options according to your specific needs.

Click Save.

Creating a Module Mode Rsync Task

Before you create an rsync task on the host system, you must create a module on the remote system. You must define at least one module per rsyncd.conf(5) on the rsync server. The Rsync Daemon application is available in situations where configuring TrueNAS as an rsync server with an rsync module is necessary. If the non-TruNAS remote server includes an rsync service, make sure it is turned on.

After configuring the rsync server, go to Data Protection and click Add on the Rsync Tasks widget to open the Add Rsync Task screen.

Figure 1: Add Rsync Task Source and Remote

Enter or browse to the dataset or folder to sync with the remote server. Use the arrow_right to the left of the /mnt folder and each folder listed on the tree to expand and browse through, then click on the name to populate the path field.

Browsing to select a path

Click the arrow to the left of the folder icon to expand that folder and show any child datasets and directories. A solid folder icon shows for datasets and an outlined folder for directories. A selected dataset or directory folder and name shows in blue.

Click in the User field then select the user from the dropdown list. The user must have permissions to run an rsync on the remote server.

Set the Direction for the rsync task. Select Pull to copy from the remote server to TrueNAS or Push to copy from TrueNAS to the remote server.

Select Module as the connection mode from the Rsync Mode dropdown.

Enter the remote host name or IP in Remote Host. Use the format username@remote_host when the username differs from the host entered into the Remote Host field.

Figure 3: Add Rsync Task Schedule and More Options

Set the schedule for when to run this task, and any other options you want to use. If you need a custom schedule, select Custom to open the advanced scheduler window.

Advanced Scheduler

Choosing a Presets option populates in the rest of the fields. To customize a schedule, enter crontab values for the Minutes/Hours/Days.

These fields accept standard cron values. The simplest option is to enter a single number in the field. The task runs when the time value matches that number. For example, entering 10 means that the job runs when the time is ten minutes past the hour.

An asterisk (*) means match all values.

You can set specific time ranges by entering hyphenated number values. For example, entering 30-35 in the Minutes field sets the task to run at minutes 30, 31, 32, 33, 34, and 35.

You can also enter lists of values. Enter individual values separated by a comma (,). For example, entering 1,14 in the Hours field means the task runs at 1:00 AM (0100) and 2:00 PM (1400).

A slash (/) designates a step value. For example, entering * in Days runs the task every day of the month. Entering */2 runs it every other day.

Combining the above examples creates a schedule running a task each minute from 1:30-1:35 AM and 2:30-2:35 PM every other day.

TrueNAS has an option to select which Months the task runs. Leaving each month unset is the same as selecting every month.

The Days of Week schedules the task to run on specific days in addition to any listed days. For example, entering 1 in Days and setting Wed for Days of Week creates a schedule that starts a task on the first day of the month and every Wednesday of the month.

The Schedule Preview displays when the current settings mean the task runs.

Examples of CRON syntax

Syntax	Meaning	Examples
*	Every item.	* (minutes) = every minute of the hour. * (days) = every day.
*/N	Every N^th item.	/15 (minutes) = every 15th minute of the hour. /3 (days) = every 3rd day. */3 (months) = every 3rd month.
Comma and hyphen/dash	Each stated item (comma) Each item in a range (hyphen/dash).	1,31 (minutes) = on the 1st and 31st minute of the hour. 1-3,31 (minutes) = on the 1st to 3rd minutes inclusive, and the 31st minute, of the hour. mon-fri (days) = every Monday to Friday inclusive (every weekday). mar,jun,sep,dec (months) = every March, June, September, December.

You can specify days of the month or days of the week.

TrueNAS lets users create flexible schedules using the available options. The table below has some examples:

Desired schedule	Values to enter
3 times a day (at midnight, 08:00 and 16:00)	months=; days=; hours=0/8 or 0,8,16; minutes=0 (Meaning: every day of every month, when hours=0/8/16 and minutes=0)
Every Monday/Wednesday/Friday, at 8.30 pm	months=*; days=mon,wed,fri; hours=20; minutes=30
1st and 15th day of the month, during October to June, at 00:01 am	months=oct-dec,jan-jun; days=1,15; hours=0; minutes=1
Every 15 minutes during the working week, which is 8am - 7pm (08:00 - 19:00) Monday to Friday	Note that this requires two tasks to achieve: (1) months=; days=mon-fri; hours=8-18; minutes=/15 (2) months=*; days=mon-fri; hours=19; minutes=0 We need the second scheduled item, to execute at 19:00, otherwise we would stop at 18:45. Another workaround would be to stop at 18:45 or 19:45 rather than 19:00.

Select the Enabled to enable the task. Leave cleared to disable the task but not delete the configuration. You can still run the rsync task by going to Data Protection and clicking then the Run Now icon for the rsycn task.

Click Save.