Backup MariaDB Databases to Linode Object Storage with Restic

It is vital to have backups of your databases to allow you to restore in the event of a server fault, a user error or —worst-case— a hacking or defacing of your website or applications.

To be successful, backups should be automatic, reliable, and secure. This guide explains how to configure Restic on your Linode to backup your MariaDB (or MySQL) databases onto Linode Object Storage, so they can be recovered even if your Linode is no longer accessible.

Restic is a backup utility written in Go. It is cross-platform and works on most Linux distributions with a kernel newer than 2.6.23. Each backup is stored as a snapshot in a repository. The repository can be stored on most cloud storage providers, or even in a separate directory on your Linode (not recommended.) This guide explains how to use Linode Object Storage to hold your backup repository.

Note

MariaDB is a fork of MySQL. Where you see a reference to MariaDB in this guide, it should apply to MySQL also.

Note

The steps in this guide require root privileges, and commands are run with sudo unless otherwise noted. For more information on privileges, see our Users and Groups guide.

1. If you have not already done so, create a Linode account and Compute Instance. See our Getting Started with Linode and Creating a Compute Instance guides.

2. Follow our Setting Up and Securing a Compute Instance guide to update your system. You may also wish to set the timezone, configure your hostname, create a limited user account, and harden SSH access.

3. Install MariaDB on your Linode by following the How to Install MariaDB guide that is appropriate for your Linode’s distribution.

4. Create an Object Storage bucket to hold your backup repository. Follow the Create a Bucket guide if you do not already have one.

   Caution

   Object Storage is similar to a subscription service. Once enabled, you will be billed at the flat rate regardless of whether or not there are active buckets on your account. You must Cancel Object Storage to stop billing for this service.

5. Generate Object Storage access keys.

6. Ensure your Linode has the wget and bzip2 utilities installed. Install them with the following commands:

   CentOS / Fedora

   yum install wget bzip2
   

   Ubuntu / Debian

   apt install wget bzip
   

1. Download the latest version of Restic from the Github Releases page (version 0.11.0 at the time of writing):

    wget https://github.com/restic/restic/releases/download/v0.11.0/restic_0.11.0_linux_amd64.bz2
   

   Note

   Ensure you select the correct file for your system. The above command is correct for most Linux distributions on Linode.

2. Extract the downloaded file:

    bzip2 -d restic_0.11.0_linux_amd64.bz2
   

3. Move the extracted file to your system’s $PATH and make it executable for all users:

    sudo mv restic_0.11.0_linux_amd64 /usr/local/bin/restic
    sudo chmod ugo+x /usr/local/bin/restic
   

4. You can now run Restic using the command restic:

    restic version
   

   You should see a similar output:

   restic 0.11.0 compiled with go1.15.3 on linux/amd64

Note

Create an Object Storage access key pair if you have not done so already.

1. Configure Restic to use your Object Storage access key pair and to use the bucket you created in the Before You Begin section of this guide. Replace your-key, your-secret, and us-east-1.linodeobjects.com/your-bucket-name with your own values.

    AWS_ACCESS_KEY_ID=your-key AWS_SECRET_ACCESS_KEY=your-secret restic -r s3:us-east-1.linodeobjects.com/your-bucket-name init
   

   Note

   The above command references the us-east-1 cluster, which is located in the Newark, NJ cluster region. If your bucket is located in a different cluster region, replace us-east-1 with the appropriate cluster name.

   For example, for the Frankfurt, DE cluster region the command is:

   AWS_ACCESS_KEY_ID=your-key AWS_SECRET_ACCESS_KEY=your-secret restic -r s3:eu-central-1.linodeobjects.com/your-bucket-name init
   

   Caution

   Ensure the name of your bucket is correct. If the bucket does not exist, Restic creates a new bucket for you in the cluster region you designate.

2. Following the prompt, set a password to encrypt your repository’s data. Enter your desired password twice, and you see an output confirming that your repository has been created:

   enter password for new repository:
   enter password again:
   created restic repository c3ffbd1ea6 at s3:us-east-1.linodeobjects.com/restic-backups-example
   
   Please note that knowledge of your password is required to access
   the repository. Losing your password means that your data is
   irrecoverably lost.

   Caution

   Store this password securely and somewhere other than your Linode. Your backups are inaccessible without the password.

Your access key, secret key, and password are required every time Restic communicates with your repository. To make it easier to work with your repository, create a shell script containing your credentials.

Note

The examples in this section use the Nano text editor. Refer to the Nano Text Editor Commands guide if you’re not familiar with Nano.

1. To keep your credentials secure, using a text editor, create the example script in the root user’s home directory, and run all your Restic scripts as the root user. The example uses the Nano text editor.

    sudo nano /root/restic_params
   

   Copy and paste the example file’s content and replace your-key, and your-secret with your own Object Storage account’s access key credentials.

   File: /root/restic_params

   1 2	export AWS_ACCESS_KEY_ID=your-key export AWS_SECRET_ACCESS_KEY=your-secret

   Note

   Whenever you want to use Restic, import this file using the command below or include it in your user’s login script:

   source /root/restic_params
   

2. Create a password file to hold your Restic password:

    sudo nano /root/restic_pw
   

   Enter your Restic password and save the file.

   File: /root/restic_pw

   1	YourPasswordGoesHere

   Note

   You can pass your password filename to Restic using the -p flag:

   restic -p /root/restic_pw ...
   

Note

In this section’s commands, remember to replace your-bucket-name and us-east-1.linodeobjects.com with the name of your Object Storage bucket and its cluster hostname.

The mysqldump utility is used to dump the contents of a database to a file stored on your Linode. This section’s example script, loops through all databases on your server and dumps each one to its own SQL file.

1. Create a file in your /usr/local/bin directory:

    sudo nano /usr/local/bin/backup_mariadb
   

2. Copy the following contents into the file:

   File: /usr/local/bin/backup_mariadb

   1 2 3 4 5

   #!/bin/bash PATH="/usr/local/bin:$PATH" source /root/restic_params mysql --defaults-extra-file=/root/mysql_cnf -N -e 'show databases' | while read dbname; do /usr/bin/mysqldump --defaults-extra-file=/root/mysql_cnf --complete-insert "$dbname" > "/var/backups/mariadb/$dbname".sql; done restic -r s3:us-east-1.linodeobjects.com/your-bucket-name -p /root/restic_pw backup /var/backups/mariadb

3. Make the script executable and create the folder to store the backup files (if it doesn’t already exist):

    sudo chmod u+x /usr/local/bin/backup_mariadb
    sudo mkdir -p /var/backups/mariadb/
   

4. Line 3 of the script refers to a MySQL configuration file named msql_cnf, which is used to authenticate with your database. Create this file under your /root directory and add the username and password for your database:

    sudo nano /root/mysql_cnf
   

   Copy and past the contents of the example file and replace the values of your-database-username and your-database-password with your own.

   File: /root/mysql_cnf

   1 2 3

   [client] user="your-database-username" password="your-database-password"

5. Run your first backup using the script you created:

    sudo backup_mariadb
   

   You should see a similar output:

   mysqldump: Got error: 1044: "Access denied for user 'root'@'localhost' to database 'information_schema'" when using LOCK TABLES
   mysqldump: Got error: 1142: "SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'accounts'" when using LOCK TABLES
   repository 1689c602 opened successfully, password is correct
   
   Files:           4 new,     0 changed,     0 unmodified
   Dirs:            2 new,     0 changed,     0 unmodified
   Added to the repo: 470.844 KiB
   
   processed 4 files, 469.825 KiB in 0:01
   snapshot 81072f28 saved

6. Verify that your backups have been created. You should see one backup file per database:

    ls -al /var/backups/mariadb
   

   The output displays all backup files stored in the backups directory you created:

   total 492
   drwxr-xr-x 2 root root   4096 Jul 21 19:47 .
   drwxr-xr-x 3 root root   4096 Jul 21 19:46 ..
   -rw-r--r-- 1 root root    830 Jul 21 19:47 information_schema.sql
   -rw-r--r-- 1 root root 479441 Jul 21 19:47 mysql.sql
   -rw-r--r-- 1 root root    830 Jul 21 19:47 performance_schema.sql
   -rw-r--r-- 1 root root   1292 Jul 21 19:47 wordpress.sql

7. Executing the script also creates a snapshot in your Restic repository. Use Restic’s snapshot command to view it:

    sudo /bin/bash -c "source /root/restic_params; restic -r s3:us-east-1.linodeobjects.com/your-bucket-name -p /root/restic_pw snapshots"
   

   Restic returns a similar output:

   repository 1689c602 opened successfully, password is correct
   ID        Time                 Host        Tags        Paths
   ---------------------------------------------------------------------------
   81072f28  2020-07-21 19:47:19  li1356-54               /var/backups/mariadb
   ---------------------------------------------------------------------------
   1 snapshots

Linux has several ways of running a job on a defined schedule. This section outlines several common methods that you can use to configure the backup script to run periodically. Read through the methods and select one that suits your needs.

Note

When choosing how often to run your script, consider your databases’ usage, how much data you could potentially lose, and the storage space required.

System Cron jobs exist as entries in the /etc/crontab file. Open your systems crontab file for editing with the following command:

sudo crontab -e

Add a line pointing to your backup script. This example runs the backup every hour, on the hour. See the Schedule tasks with Cron article for additional scheduling options.

0 * * * * /usr/local/bin/backup_mariadb > /tmp/mariadb-backup-log.txt 2>&1

Systemd can run commands (known as units) on a periodic basis using timers. You can use systemd commands to monitor when the timers and commands last ran, and the output from running the commands.

To schedule a command, you need two configuration files: the service file which includes the commands to run and a timer file which defines when to run the service.

Create the service configuration file and copy and paste the contents of the example:

sudo nano /etc/systemd/system/backup-mariadb.service

File: /etc/systemd/system/backup-mariadb.service

1 2 3 4 5

[Unit] Description=Backup MariaDB databases [Service] ExecStart=/usr/local/bin/backup_mariadb Environment=USER=root HOME=/root

Create the timer configuration file and copy and paste the contents of the example. The OnCalendar line instructs Systemd when to execute the service file’s commands. In the example, the service file’s commands are run on-the-hour, every hour.

sudo nano /etc/systemd/system/backup-mariadb.timer

File: /etc/systemd/system/backup-mariadb.timer

1 2 3 4 5 6

[Unit] Description=Backup MariaDB databases [Timer] OnCalendar=*-*-* *:00:00 [Install] WantedBy=timers.target

When you are satisfied with your timer’s configurations, enable the timer:

sudo systemctl enable --now backup-mariadb.timer

You can monitor all your system’s timers with the following command:

sudo systemctl list-timers

You should see a similar output:

NEXT                        LEFT          LAST                        PASSED        UNIT                         ACTIVATES
Mon 2020-07-20 16:00:00 BST 35min left    Mon 2020-07-20 15:00:03 BST 24min ago     backup-mariadb.timer         backup-mariadb.service

The NEXT and LEFT column tells you the exact time and how long until the timer executes the service file next. The LAST and PASSED columns display information on when the timer last executed the service file.

Log into your Linode Cloud Manager account and view the Object Storage bucket you created to store your Restic backups. You should see a set of files like the ones displayed in the screenshot below. These files collectively make up the Restic repository; you will not see your individual database backup files.

To explore the backups and files held within the Restic repository, you must issue the restic command from the machine that you installed Restic on when following the steps in the Before You Begin section.

It can get tedious typing out the arguments to the Restic command. To make life easier for maintenance and daily management, create an alias for the command with the arguments you need.

Note

Because the credentials that Restic uses were created under the root user’s home folder, the example alias in this section only works for the root user.

In your root user’s .profile file, add the lines in the example. For example, on an Ubuntu system this file is located in /root/.profile. To learn more about creating reusable aliases, see the How to Add the Linux alias Command in the .bashrc File guide.

source /root/restic_params
alias myrestic='restic -r s3:us-east-1.linodeobjects.com/your-bucket-name -p /root/restic_pw'

After logging out of your system and back in again, you can run restic using your aliased command:

myrestic snapshots

Backups are not useful if you cannot restore them. It’s a good idea to test out your backups once in a while. To restore the latest usable backup from Restic, run the restore latest command:

restic -r s3:us-east-1.linodeobjects.com/your-bucket-name -p /root/restic_pw restore latest -t /root

Note

The -t option tells Restic where to restore your backup. Restic restores your backup’s files and recreates the full directory structure that existed at the time the backup was taken.

For example, consider the backup file /var/backups/mariadb/wordpress.sql. Restoring a backup containing this file to a target of /home/myuser results in the file being restored as:

/home/myuser/var/backups/mariadb/wordpress.sql

To restore a backup from a particular point-in-time, issue the example command to find the snapshot ID for the specific backup.

sudo /bin/bash -c "source /root/restic_params; restic -r s3:us-east-1.linodeobjects.com/your-bucket-name -p /root/restic_pw snapshots"

The output resembles the example, where the first column displays the snapshot ID:

repository 1689c602 opened successfully, password is correct
ID        Time                 Host        Tags        Paths
---------------------------------------------------------------------------
81072f28  2020-07-21 19:47:19  li1356-54               /var/backups/mariadb
---------------------------------------------------------------------------
1 snapshots

Pass the selected ID to the restore command instead of latest. Replace 81072f28 in the example with your own snapshot ID:

sudo /bin/bash -c "source /root/restic_params; restic -r s3:us-east-1.linodeobjects.com/your-bucket-name -p /root/restic_pw restore 81072f28 -t /root"

The above commands restore all databases taken in the backup. If you only want a selected backup, pass the filename using the -i option, along with either latest or the snapshot ID:

sudo /bin/bash -c "source /root/restic_params; restic -r s3:us-east-1.linodeobjects.com/your-bucket-name -p /root/restic_pw restore 81072f28 -i wordpress.sql -t /root"

Your backup repository’s size can grow very quickly, especially if you backup a large database every hour.

Restic can automatically clean-up your backup snapshots according to a flexible policy using snapshot policies.

Consider automatically running a policy using the forget command on a frequent basis (e.g. daily) to keep your backup repository’s size down. Refer to the snapshot policies article for more details.

Note

Don’t forget to pass the --prune option to the forget command or the space won’t actually be freed from your repository.

Pruning a repository can take significant time and stops new backups from taking place while it is being run, so it is best to run it often and non-interactively.

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

• mysqldump - MariaDB Knowledge Base
• Preparing a new Restic repository
• Backing up
• Removing snapshots according to a policy