Bob Learns System Backup and Recovery on AlmaLinux

“Bob Learns System Backup and Recovery”. In this chapter, Bob will learn how to create backups, automate them, and restore data if something goes wrong—a crucial skill for any sysadmin!

1. Introduction: Bob’s Backup Awakening

After a long day of setting up scripts and configurations, Bob accidentally deletes a critical file. Thankfully, he recovers it, but the experience serves as a wake-up call—he needs to set up a proper backup system to avoid any future disasters. Bob’s ready to learn how to create, automate, and test backups on AlmaLinux.

“Better safe than sorry. Time to back everything up!” Bob says, determined to make sure his data is secure.

2. Overview of Backup Strategies

Before diving in, Bob researches different backup strategies and learns about the three main types:

• Full Backups: A complete copy of all selected files, offering full restoration but using the most storage and time.
• Incremental Backups: Only the changes since the last backup are saved, saving storage space but taking longer to restore.
• Differential Backups: Copies changes since the last full backup, a middle-ground option that saves storage while providing faster restoration.

After reviewing his options, Bob decides to start with full backups and plans to explore incremental backups later.

“I’ll start with full backups, then add automation and incremental backups as I go,” he notes, feeling organized.

3. Creating a Basic Backup with tar

To practice, Bob learns how to use tar to create a compressed backup of his /home/bob/documents directory.

• Creating a Compressed Backup: He runs the following command to compress his files into a .tar.gz archive:

  tar -czf /home/bob/backups/documents_backup_$(date +\%Y-\%m-\%d).tar.gz /home/bob/documents
  

  • -c: Creates a new archive.
  • -z: Compresses the archive with gzip.
  • -f: Specifies the filename.
  • $(date +\%Y-\%m-\%d): Adds the current date to the filename for easy tracking.

Bob successfully creates a backup file, and he’s pleased to see it listed in his /home/bob/backups directory.

“Alright, my documents are safe for now,” he thinks with relief.

4. Automating Backups with rsync and Cron

Bob decides that manual backups are too easy to forget, so he automates the process with rsync, a powerful tool for syncing files and directories.

• Setting Up rsync for Incremental Backups: rsync only copies changes, which saves time and space. Bob sets up rsync to back up his documents to an external directory:

  rsync -av --delete /home/bob/documents /home/bob/backups/documents
  

  • -a: Archives files, preserving permissions, timestamps, and ownership.
  • -v: Verbose mode to see what’s being copied.
  • --delete: Deletes files in the backup that no longer exist in the source.

• Automating with Cron: To schedule this task weekly, Bob edits his crontab:

  crontab -e
  

  And adds this line:

  0 2 * * 0 rsync -av --delete /home/bob/documents /home/bob/backups/documents
  

  This runs rsync every Sunday at 2 a.m., ensuring his documents are always backed up without him needing to remember.

“Automated backups—now I can sleep easy!” Bob says, satisfied with his new setup.

5. Testing and Restoring Backups

Bob knows that a backup system isn’t truly effective until he’s tested it. He decides to simulate a file recovery scenario to ensure he can restore his files if something goes wrong.

• Deleting a Test File: He removes a file from his /home/bob/documents directory as a test.

• Restoring the File from Backup: To restore, Bob uses rsync in reverse:

  rsync -av /home/bob/backups/documents/ /home/bob/documents/
  

  This command copies the file back to its original location. He confirms that the file is successfully restored.

• Extracting from tar Archive: Bob also practices restoring files from his tar backup. To extract a specific file from the archive, he runs:

  tar -xzf /home/bob/backups/documents_backup_2023-11-10.tar.gz -C /home/bob/documents filename.txt
  

  This command restores filename.txt to the original directory.

“Testing backups is just as important as creating them,” Bob notes, relieved to see his data safely restored.

6. Conclusion: Bob’s Backup Confidence

Now that he has a reliable backup system in place, Bob feels prepared for anything. Between his scheduled rsync backups, tar archives, and his ability to restore files, he knows he can handle unexpected data loss.

Next, he’s ready to dive into AlmaLinux’s package management and repositories, learning to install and manage software with ease.

Stay tuned for the next chapter: “Bob Explores Package Management and Repositories!”