Lesson 10 - Backup and Restore on Ubuntu

In this lesson, we will learn how to back up and restore data on a Linux system using tar and rsync, set up automated backups with cron, and restore data from backups. Data backup is crucial for protecting your data from loss due to system failures or other issues.

1. Using tar and rsync for Data Backup

tar: Creating Backups

The tar command is used to create backups of files and directories by archiving them into a tarball file.

Detailed Examples:

1. Create a backup of the /home/user/Documents directory:

   tar -cvf backup.tar /home/user/Documents
   

   This command creates a backup.tar file containing all files and directories in /home/user/Documents.

2. Create a compressed backup of the /home/user directory:

   tar -czvf backup.tar.gz /home/user
   

   This command creates a compressed backup.tar.gz file containing all files and directories in /home/user.

3. Extract files from a tarball:

   tar -xvf backup.tar
   

   This command extracts all files and directories from backup.tar to the current directory.

rsync: Synchronizing Backups

The rsync command is used to back up and synchronize files and directories between different locations.

Detailed Examples:

1. Backup the /home/user/Documents directory to the /backup directory:

   rsync -av /home/user/Documents /backup
   

   This command copies all files and directories from /home/user/Documents to the /backup directory, preserving permissions and directory structure.

2. Backup the directory over SSH:

   rsync -avz /home/user/Documents user@remote:/backup
   

   This command copies all files and directories from /home/user/Documents to the /backup directory on the remote server remote, using SSH for secure transfer.

2. Setting Up Automated Backups with cron

cron is a powerful tool that allows you to automate tasks on a Linux system.

Creating an Automated Backup Task with cron

1. Open the crontab file:

   crontab -e
   

2. Add the following line to the crontab file to set up a daily backup at 2 AM:

   0 2 * * * tar -czvf /backup/backup_$(date +\%F).tar.gz /home/user
   

   This command creates a compressed backup of the /home/user directory and saves it to the /backup directory with the current date in the filename.

Detailed Example:

1. Set up a daily backup:

   0 2 * * * rsync -av /home/user/Documents /backup
   

   This line runs the rsync command to back up the /home/user/Documents directory to the /backup directory every day at 2 AM.

3. Restoring Data from Backups

Extracting and Restoring from a tarball

1. Extract files from a tarball:

   tar -xzvf /backup/backup_2024-06-28.tar.gz -C /home/user
   

   This command extracts the backup_2024-06-28.tar.gz file to the /home/user directory.

Detailed Example:

1. Restore from a tarball:

   tar -xzvf /backup/backup_2024-06-28.tar.gz -C /home/user
   

   This command extracts the backup_2024-06-28.tar.gz file to the /home/user directory, restoring all backed-up files and directories.

Using rsync to Restore Data

1. Restore data from the backup directory:

   rsync -av /backup /home/user/Documents
   

   This command copies all files and directories from the /backup directory to the /home/user/Documents directory.

Detailed Example:

1. Restore using rsync:

   rsync -av /backup /home/user/Documents
   

   This command copies all files and directories from the /backup directory to the /home/user/Documents directory, restoring the backed-up data.

Conclusion

In this lesson, you have learned how to use tar and rsync to back up and restore data, as well as how to set up automated backups with cron. These skills are essential for ensuring that your data is always protected and can be quickly restored when needed. Practice these commands to become proficient in managing backups on your Linux system.