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Deep Thought

Linux Exercise 6 - Compression and Backup

Exercise: Archiving, Compressing, and Backing Up Files in UNIX/Linux

Objective

Learn how to:

  • Create and extract archives using tar and cpio.
  • Apply compression with compress, gzip, and modern alternatives.
  • Combine commands for efficient backup workflows.
  • Interpret the results and verify integrity.

Tasks

Task 1: Create a tar Archive

  • Archive the contents of your home directory (including subdirectories) into a single file.
  • Expected outcome: A .tar file containing all files and directories from your home directory.

Task 2: Compress the tar Archive

  • Compress the archive you created using gzip.
  • Compare the size of the compressed file with the original .tar file.
  • Expected outcome: A .tar.gz file that is smaller than the original archive.

Task 3: Create a cpio Archive

  • Use find and cpio to create an archive of your home directory.
  • Compress this archive using compress or gzip.
  • Expected outcome: A compressed archive file created with cpio.

Task 4: Extract and Verify

  • Extract both the tar and cpio archives into separate directories.
  • Verify that the extracted files match the original files (check file count and structure).
  • Expected outcome: Two restored directories identical to the original.

Task 5: List Archive Contents

  • Without extracting, list the contents of your tar archive.
  • Expected outcome: A detailed list of files and directories inside the archive.

Task 6: Use Modern Compression

  • Create a tar archive of /etc and compress it using bzip2 or xz.
  • Compare the size and compression time with the gzip-compressed archive.
  • Expected outcome: A .tar.bz2 or .tar.xz file, likely smaller than the gzip version.

Task 7: Create a ZIP Archive

  • Create a .zip archive of your home directory.
  • Compare its size and compression ratio with the .tar.gz archive.
  • Expected outcome: A .zip file and an observation about cross-platform compatibility.

Task 8: Incremental Backup Simulation

  • Use rsync to copy your home directory to a backup location.
  • Modify a few files and run rsync again.
  • Expected outcome: Only changed files should be updated in the backup.

Task 9: Best Practices Check

  • After completing all tasks, reflect on:
    • Which compression method gave the best ratio?
    • Which tool was fastest?
    • Which method is best for large backups?

📑 Protocol (What to Hand In)

Each student must create a protocol (log) containing:

  • Command executed
  • Output received (full or partial if very long)
  • Explanation (1–2 sentences) of what the command did
  • Observation/interpretation of what they learned

Example:

Command: file sample.zip
Output: sample.zip: Zip archive data, at least v2.0 to extract
Explanation: Identified sample.zip as a compressed archive file.
Observation: Shows that zip files are binary and need archive tools to inspect contents.
Terminal window
Command: sudo tail -f /var/log/syslog
Output: (live log output appears)
Explanation: Monitors new log entries in real-time.
Observation: Useful for watching system activity as it happens.