Archive backup compress unpack and uncompress files Optional

In this lesson, we’ll cover how to archive files in Linux using tar, compress those archives, and prepare them for remote backups. This workflow is essential for system administrators and DevOps engineers who need reliable, space-efficient backups.

Typical backup workflow:

1. Archive: Pack multiple files and directories into one file (e.g., backup.tar).
2. Compress: Shrink the archive size (e.g., backup.tar.gz).
3. Transfer: Copy the compressed archive to a remote server, shared drive, or cloud storage.

We’ll focus first on archiving with tar, then move on to compression and remote backups.

Why Use tar?

Tar (tape archive) was originally designed for magnetic tapes but remains the de facto tool for:

• Bundling multiple files or directories into a single tarball (.tar).
• Preserving file metadata: permissions, timestamps, and ownership.

Common tar Commands at a Glance

Listing Contents of an Existing Archive

To preview what’s inside archive.tar:

tar --list --file archive.tar    # Long form
tar -tf archive.tar              # Short form

This displays:

file1
file2
file3

Creating and Appending to a Tarball

Create a New Archive

# Long form
tar --create --file archive.tar file1

# Short form
tar -cf archive.tar file1

Append Files or Directories

# Add a single file
tar --append --file archive.tar file2
# Short form
tar -rf archive.tar file2

# Add an entire directory
tar --create --file archive.tar pictures/
# Short form
tar -cf archive.tar pictures/

• Using a relative path like pictures/ stores entries as pictures/....
• An absolute path (/home/aaron/pictures/) preserves the full directory structure inside the archive.

Extracting an Archive

Always list contents before extracting:

tar --list --file archive.tar
tar -tf archive.tar

Example output:

Pictures/
Pictures/family_dog.jpg

Extract into Current Directory

tar --extract --file archive.tar
# or
tar -xf archive.tar

If you’re in /home/aaron/work, the files will unpack into /home/aaron/work/Pictures/.

Extract to a Specific Directory

tar --extract --file archive.tar --directory /tmp
# or
tar -xf archive.tar -C /tmp

Preserving Ownership and Permissions

By default, tar preserves permissions and ownership metadata in the archive. However, regular users cannot restore files to other owners. To fully retain all metadata, run extraction as root:

sudo tar -xf archive.tar -C /desired/path

References

• GNU tar Manual
• Linux File Permissions