6. Tasks — TrueNAS Administrator Guide 9.3-STABLE Table of Contents

# 6. Tasks

The Tasks section of the administrative GUI can be used to configure the following repetitive tasks:

- Cron Jobs: allows you to schedule a command or script to automatically execute at a specified time
- Init/Shutdown Scripts: used to configure a command or script to automatically execute during system startup or shutdown
- Rsync Tasks: allows you to schedule data synchronization to another system
- S.M.A.R.T. Tests: allows you to schedule how often disk tests occur

Each of these tasks is described in more detail in this section.

## 6.1. Cron Jobs

cron(8) is a daemon that runs a command or script on a regular schedule as a specified user. Typically, the user who wishes to schedule a task manually creates a crontab(5) using syntax that can be perplexing to new Unix users. The TrueNAS® GUI makes it easy to schedule when you would like the task to occur.

Note

due to a limitation in FreeBSD, users with account names that contain spaces or exceed 17 characters are unable to create cron jobs.

Figure 6.1.1: Creating a Cron Job shows the screen that opens when you click Tasks ‣ Cron Jobs ‣ Add Cron Job.

Table 6.1a summarizes the configurable options when creating a cron job.

Table 6.1a: Cron Job Options

Setting | Value | Description
--- | --- | ---
User | drop-down menu | make sure the selected user has permission to run the specified command or script
Command | string | the full path to the command or script to be run; if it is a script, test it at the command line first to make sure that it works as expected
Short description | string | optional
Minute | slider or minute selections | if use the slider, cron job occurs every N minutes; if use minute selections, cron job occurs at the highlighted minutes
Hour | slider or hour selections | if use the slider, cron job occurs every N hours; if use hour selections, cron job occurs at the highlighted hours
Day of month | slider or month selections | if use the slider, cron job occurs every N days; if use day selections, cron job occurs on the highlighted days each month
Month | checkboxes | cron job occurs on the selected months
Day of week | checkboxes | cron job occurs on the selected days
Redirect Stdout | checkbox | disables emailing standard output to the root user account
Redirect Stderr | checkbox | disables emailing errors to the root user account
Enabled | checkbox | uncheck if you would like to disable the cron job without deleting it

Created cron jobs will be listed in “View Cron Jobs”. If you highlight the entry for a cron job, buttons will be displayed to “Edit”, “Delete”, or “Run Now”.

## 6.2. Init/Shutdown Scripts

TrueNAS® provides the ability to schedule commands or scripts to run at system startup or shutdown.

Figure 6.2.1: Add an Init/Shutdown Script shows the screen that opens when you click Tasks ‣ Init/Shutdown Scripts ‣ Add Init/Shutdown Script. Table 6.2a summarizes the available options.

When scheduling a command, make sure that the command is in your path or give the full path to the command. One way to test the path is to type which command_name. If the command is not found, it is not in your path.

When scheduling a script, make sure that the script is executable and has been fully tested to ensure that it achieves the desired results.

Table 6.2a: Options When Adding an Init/Shutdown Script

Setting | Value | Description
--- | --- | ---
Type | drop-down menu | select from Command (for an executable) or Script (for an executable script)
Command | string | if Command is selected, input the command plus any desired options; if Script is selected, browse to the location of the script
When | drop-down menu | select when the command/script will run; choices are Pre Init (very early in boot process before filesystems are mounted), Post Init (towards end of boot process before TrueNAS services are started), or Shutdown

## 6.3. Rsync Tasks

Rsync is a utility that automatically copies specified data from one system to another over a network. Once the initial data is copied, rsync reduces the amount of data sent over the network by sending only the differences between the source and destination files. Rsync can be used for backups, mirroring data on multiple systems, or for copying files between systems.

To configure rsync, you need to configure both ends of the connection:

- the rsync server: this system pulls (receives) the data. This system is referred to as PULL in the configuration examples.
- the rsync client: this system pushes (sends) the data. This system is referred to as PUSH in the configuration examples.

TrueNAS® can be configured as either an rsync client or an rsync server. The opposite end of the connection can be another TrueNAS® system or any other system running rsync. In TrueNAS® terminology, an rysnc task defines which data is synchronized between the two systems. If you are synchronizing data between two TrueNAS® systems, create the rsync task on the rsync client.

TrueNAS® supports two modes of rsync operation:

- rsync module mode: exports a directory tree, and its configured settings, as a symbolic name over an unencrypted connection. This mode requires that at least one module be defined on the rsync server. It can be defined in the TrueNAS® GUI under Services ‣ Rsync ‣ Rsync Modules. In other operating systems, the module is defined in rsyncd.conf(5).
- rsync over SSH: synchronizes over an encrypted connection. Requires the configuration of SSH user and host public keys.

This section summarizes the options when creating an Rsync Task. It then provides a configuration example between two TrueNAS® systems for each mode of rsync operation.

Note

if there is a firewall between the two systems or if the other system has a built-in firewall, make sure that TCP port 873 is allowed.

Figure 6.3.1: Adding an Rsync Task shows the screen that appears when you click Tasks ‣ Rsync Tasks ‣ Add Rsync Task. Table 6.3a summarizes the options that can be configured when creating an rsync task.

Table 6.3a: Rsync Configuration Options

Setting | Value | Description
--- | --- | ---
Path | browse button | browse to the path that you wish to copy; note that a path length greater than 255 characters will fail
User | drop-down menu | specified user must have permission to write to the specified directory on the remote system; due to a limitation in FreeBSD, the user name can not contain spaces or exceed 17 characters
Remote Host | string | IP address or hostname of the remote system that will store the copy; use the format username@remote_host if the username differs on the remote host
Remote SSH Port | integer | only available in Rsync over SSH mode; allows you to specify an alternate SSH port other than the default of 22
Rsync mode | drop-down menu | choices are Rsync module or Rsync over SSH
Remote Module Name | string | only appears when using Rsync module mode, at least one module must be defined in rsyncd.conf(5) of rsync server or in the “Rsync Modules” of another system
Remote Path | string | only appears when using Rsync over SSH mode, input the existing path on the remote host to sync with (e.g. /mnt/volume); note that maximum path length is 255 characters
Validate Remote Path | checkbox | if the “Remote Path” does not yet exist, check this box to have it automatically created
Direction | drop-down menu | choices are Push or Pull; default is to push to a remote host
Short Description | string | optional
Minute | slider or minute selections | if use the slider, sync occurs every N minutes; if use minute selections, sync occurs at the highlighted minutes
Hour | slider or hour selections | if use the slider, sync occurs every N hours; if use hour selections, sync occurs at the highlighted hours
Day of month | slider or day selections | if use the slider, sync occurs every N days; if use day selections, sync occurs on the highlighted days
Month | checkboxes | task occurs on the selected months
Day of week | checkboxes | task occurs on the selected days of the week
Recursive | checkbox | if checked, copy will include all subdirectories of the specified volume
Times | checkbox | preserve modification times of files
Compress | checkbox | recommended on slow connections as reduces size of data to be transmitted
Archive | checkbox | equivalent to -rlptgoD (recursive, copy symlinks as symlinks, preserve permissions, preserve modification times, preserve group, preserve owner (super-user only), and preserve device files (super-user only) and special files)
Delete | checkbox | delete files in destination directory that don’t exist in sending directory
Quiet | checkbox | suppresses informational messages from the remote server
Preserve permissions | checkbox | preserves original file permissions; useful if User is set to root
Preserve extended attributes | checkbox | both systems must support extended attributes
Delay Updates | checkbox | when checked, the temporary file from each updated file is saved to a holding directory until the end of the transfer, when all transferred files are renamed into place
Extra options | string | rsync(1) options not covered by the GUI; note that if the “*” character is used, it must be escaped between single quotes (e.g. ‘*.txt’)
Enabled | checkbox | uncheck if you would like to disable the rsync task without deleting it

If the rysnc server requires password authentication, input –password-file=/PATHTO/FILENAME in the “Extra options” box, replacing /PATHTO/FILENAME with the appropriate path to the file containing the value of the password.

Created rsync tasks will be listed in “View Rsync Tasks”. If you highlight the entry for an rsync task, buttons will be displayed to “Edit”, “Delete”, or “Run Now”.

### 6.3.1. Rsync Module Mode

This configuration example will configure rsync module mode between the two following TrueNAS® systems:

- 192.168.2.2 has existing data in `/mnt/local/images`. It will be the rsync client, meaning that an rsync task needs to be defined. It will be referred to as PUSH.
- 192.168.2.6 has an existing volume named `/mnt/remote`. It will be the rsync server, meaning that it will receive the contents of `/mnt/local/images`. An rsync module needs to be defined on this system and the rsyncd service needs to be started. It will be referred to as PULL.

On PUSH, an rsync task is defined in Tasks ‣ Rsync Tasks ‣ Add Rsync Task. In this example:

- the “Path” points to `/usr/local/images`, the directory to be copied
- the “Remote Host” points to 192.168.2.6, the IP address of the rsync server
- the “Rsync Mode” is Rsync module
- the “Remote Module Name” is backups; this will need to be defined on the rsync server
- the “Direction” is Push
- the rsync is scheduled to occur every 15 minutes
- the “User” is set to root so it has permission to write anywhere
- the “Preserve Permissions” checkbox is checked so that the original permissions are not overwritten by the root user

On PULL, an rsync module is defined in Services ‣ Rsync Modules ‣ Add Rsync Module. In this example:

- the “Module Name” is backups; this needs to match the setting on the rsync client
- the “Path” is `/mnt/remote`; a directory called `images` will be created to hold the contents of `/usr/local/images`
- the “User” is set to root so it has permission to write anywhere
- “Hosts allow” is set to 192.168.2.2, the IP address of the rsync client

Descriptions of the configurable options can be found in Rsync Modules.

To finish the configuration, start the rsync service on PULL in Services ‣ Control Services. If the rsync is successful, the contents of `/mnt/local/images/` will be mirrored to `/mnt/remote/images/`.

### 6.3.2. Rsync over SSH Mode

SSH replication mode does not require the creation of an rsync module or for the rsync service to be running on the rsync server. It does require SSH to be configured before creating the rsync task:

- a public/private key pair for the rsync user account (typically root) must be generated on PUSH and the public key copied to the same user account on PULL
- to mitigate the risk of man-in-the-middle attacks, the public host key of PULL must be copied to PUSH
- the SSH service must be running on PULL

To create the public/private key pair for the rsync user account, open Shell on PUSH. The following example generates an RSA type public/private key pair for the root user. When creating the key pair, do not enter the passphrase as the key is meant to be used for an automated task.:

    ssh-keygen -t rsa
    Generating public/private rsa key pair.
    Enter file in which to save the key (/root/.ssh/id_rsa):
    Created directory '/root/.ssh'.
    Enter passphrase (empty for no passphrase):
    Enter same passphrase again:
    Your identification has been saved in /root/.ssh/id_rsa.
    Your public key has been saved in /root/.ssh/id_rsa.pub.
    The key fingerprint is:
    f5:b0:06:d1:33:e4:95:cf:04:aa:bb:6e:a4:b7:2b:df root@truenas.local
    The key's randomart image is:
    +--[ RSA 2048]----+
    |        .o. oo   |
    |         o+o. .  |
    |       . =o +    |
    |        + +   o  |
    |       S o .     |
    |       .o        |
    |      o.         |
    |    o oo         |
    |     **oE        |
    |-----------------|
    |                 |
    |-----------------|

TrueNAS® supports the following types of SSH keys: DSA, and RSA. When creating the key, specify the type you wish to use or, if you are generating the key on another operating system, select a type of key the key generation software supports.

Note

if a different user account is used for the rsync task, use the su - command after mounting the filesystem but before generating the key. For example, if the rsync task is configured to use the user1 user account, use this command to become that user:

    su - user1

Next, view and copy the contents of the generated public key:

    more .ssh/id_rsa.pub
    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC1lBEXRgw1W8y8k+lXPlVR3xsmVSjtsoyIzV/PlQPo
    SrWotUQzqILq0SmUpViAAv4Ik3T8NtxXyohKmFNbBczU6tEsVGHo/2BLjvKiSHRPHc/1DX9hofcFti4h
    dcD7Y5mvU3MAEeDClt02/xoi5xS/RLxgP0R5dNrakw958Yn001sJS9VMf528fknUmasti00qmDDcp/kO
    xT+S6DFNDBy6IYQN4heqmhTPRXqPhXqcD1G+rWr/nZK4H8Ckzy+l9RaEXMRuTyQgqJB/rsRcmJX5fApd
    DmNfwrRSxLjDvUzfywnjFHlKk/+TQIT1gg1QQaj21PJD9pnDVF0AiJrWyWnR root@truenas.local

Go to PULL and paste (or append) the copied key into the “SSH Public Key” field of Account ‣ Users ‣ View Users ‣ root ‣ Modify User, or the username of the specified rsync user account. The paste for the above example is shown in Figure 6.3.2: Pasting the User’s SSH Public Key. When pasting the key, ensure that it is pasted as one long line and, if necessary, remove any extra spaces representing line breaks.

While on PULL, verify that the SSH service is running in Services ‣ Control Services and start it if it is not.

Next, copy the host key of PULL using Shell on PUSH. The following command copies the RSA host key of the PULL server used in our previous example. Be sure to include the double bracket >> to prevent overwriting any existing entries in the `known_hosts` file:

    ssh-keyscan -t rsa 192.168.2.6 >> /root/.ssh/known_hosts

Note

if PUSH is a Linux system, use the following command to copy the RSA key to the Linux system:

    cat ~/.ssh/id_rsa.pub | ssh user@192.168.2.6 'cat >> .ssh/authorized_keys'

You are now ready to create the rsync task on PUSH. To configure rsync SSH mode using the systems in our previous example, the configuration would be as follows:

- the “Path” points to `/mnt/local/images`, the directory to be copied
- the “Remote Host” points to 192.168.2.6, the IP address of the rsync server
- the “Rsync Mode” is Rsync over SSH
- the rsync is scheduled to occur every 15 minutes
- the “User” is set to root so it has permission to write anywhere; the public key for this user must be generated on PUSH and copied to PULL
- the “Preserve Permissions” checkbox is checked so that the original permissions are not overwritten by the root user

Once you save the rsync task, the rsync will automatically occur according to your schedule. In this example, the contents of `/mnt/local/images/` will automatically appear in `/mnt/remote/images/` after 15 minutes. If the content does not appear, use Shell on PULL to read `/var/log/messages`. If the message indicates a n (newline character) in the key, remove the space in your pasted key–it will be after the character that appears just before the n in the error message.

## 6.4. S.M.A.R.T. Tests

S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) is a monitoring system for computer hard disk drives to detect and report on various indicators of reliability. When a failure is anticipated by S.M.A.R.T., the drive should be replaced. Most modern ATA, IDE, and SCSI-3 hard drives support S.M.A.R.T.–refer to your drive’s documentation if you are unsure.

Figure 6.4.1: Adding a S.M.A.R.T. Test shows the configuration screen that appears when you click Tasks ‣ S.M.A.R.T. Tests ‣ Add S.M.A.R.T. Test. The tests that you create will be listed under “View S.M.A.R.T. Tests”. After creating your tests, check the configuration in Services ‣ S.M.A.R.T., then click the slider to “ON” for the S.M.A.R.T. service in Services ‣ Control Services. The S.M.A.R.T. service will not start if you have not created any volumes.

Note

to prevent problems, do not enable the S.M.A.R.T. service if your disks are controlled by a RAID controller as it is the job of the controller to monitor S.M.A.R.T. and mark drives as Predictive Failure when they trip.

Table 6.4a summarizes the configurable options when creating a S.M.A.R.T. test.

Table 6.4a: S.M.A.R.T. Test Options

Setting | Value | Description
--- | --- | ---
Disks | list | highlight disk(s) to monitor
Type | drop-down menu | select type of test to run; see smartctl(8) for a description of each type of test (note that some test types will degrade performance or take disk(s) offline)
Short description | string | optional
Hour | slider or hour selections | if use the slider, test occurs every N hours; if use hour selections, test occurs at the highlighted hours
Day of month | slider or day selections | if use the slider, test occurs every N days; if use day selections, test occurs on the highlighted days
Month | checkboxes | select the months when you wish the test to occur
Day of week | checkboxes | select the days of the week when you wish the test to occur

You can verify which tests will run and when by typing smartd -q showtests within Shell.

You can check the results of a test from Shell by specifying the name of the drive. For example, to see the results for disk ada0, type:

    smartctl -l selftest /dev/ada0

If you enter an email address in the “Email to report” field of Services ‣ S.M.A.R.T., the system will email the specified address when a test fails.