How to configure automatic remote backup in Linux

Most of us must have experienced the loss of valuable files and data at some point in our lives. We know the importance of backing up our files and data, but few have implemented a proper backup solution.

One of the main reasons is when a local storage system fails. Good backup strategies include creating a consistent and automatic backup and storing one of the backups in a remote location.

A common method to backup a Linux server or desktop is using rsync to transfer files to a remote SSH server. cron is then used to automate the backup process.

1. Configure passwordless SSH login from your local machine to the remote backup server.

   Related: How to SSH without password

2. Create a directory on the remote server as a backup target.

   remoteuser@remoteserver:$ mkdir -p ~/backup_folder/folder_01

3. Make sure the connecting SSH user has full access to the directory on the remote backup server.

   remoteuser@remoteserver:$ chmod -R 777 ~/backup_folder/folder_01

4. Manually run your backup script on your local machine to test if the backup operation is successful.

   localuser@localhost:$ rsync -av --delete /path/to/folder_01/ remoteuser@remoteserver:backup_folder/folder_01

   Sample of a more complete script for automated backup.

   backup.sh

   #!/bin/bash
    
   TARGET="remoteuser@remoteserver:~/backup_folder"
    
   for i in folder_01 folder_02 folder_03; do
   	rsync -av --delete $i/ $TARGET/$i;
   done
5. Check on the remote server if the files were successfully backed up.

   remoteuser@remoteserver:$ ls -l ~/backup_folder/folder_01

6. Open crontab editor on the local machine.

   localuser@localhost:$ crontab -e

7. Configure cron on your local machine to automatically run your backup script at a set time.

   # Run backup command every day on midnight, sending the logs to a file.
   0 0 * * * rsync -av --delete /path/to/folder_01/ remoteuser@remoteserver:backup_folder/folder_01 >>~/.backup.log 2>&1 

   Related: Crontab Generator

8. Save and exit the crontab editor.