Foundation

Archiving and compression are the building blocks of reliable backups on a Linux VPS. For WordPress, you are usually trying to produce a portable bundle you can validate, store off-host, and restore quickly under pressure.

Quick Summary

• tar is the default archiver for directories; it preserves paths and Unix metadata well.
• gzip/zstd/xz compress single files (SQL dumps and logs are the common targets).
• For most WordPress file backups, tar.zst (or tar.gz) is the balanced default.
• Always verify archives and do restore drills to a staging directory.

What you need to back up for WordPress

Most WordPress restores require two independent artifacts:

1. Files

• Your WordPress docroot (or at minimum wp-content/).
• Configuration you cannot regenerate (for example, wp-config.php).

2. Database

• A SQL dump from MySQL/MariaDB.

wordpress-backup-components.txt

WordPress backup = files + database dump

files: wp-content/ (uploads/plugins/themes) + config
db:    mysqldump (SQL)

Archive vs compression

• Archiving = combining many files/directories into a single file.
• Compression = reducing size (trade-offs: CPU, time, decompression speed).

archive-and-compress-mental-model.txt

many files -> tar -> archive.tar -> zstd -> archive.tar.zst

single file -> gzip/zstd/xz -> db.sql.gz / db.sql.zst / db.sql.xz

Choosing formats (practical defaults)

Use these as a starting point:

Scenario	Good default	Why
Daily file backups	tar.zst or tar.gz	Good size/speed, easy restore
Database dumps	db.sql.zst or db.sql.gz	Simple, streamable, fast
Maximum compression (cold storage)	tar.xz or .7z	Smallest size, slowest
Cross-platform sharing	.zip	Works smoothly on Windows/macOS
Encrypted archives at rest	.7z (or gpg on tarballs)	Built-in encryption and optional splitting

note

If you care about Unix ownership/permissions, prefer tar-based backups. Formats like .zip are excellent for portability, but they are not the most faithful representation of Linux file metadata.

Naming, placement, and retention

Keep backups predictable:

• Directory: /backups/ or /var/backups/ (or a mounted volume).
• Naming: include date and what it contains.

backup-name-examples.txt

wp-files-2026-03-01.tar.zst
wp-db-2026-03-01.sql.zst
wp-full-2026-03-01.tar.gz

Retention is policy, not tooling. A common starting point:

• 7 daily
• 4 weekly
• 3 monthly

Verification and restore drills

Verification is what turns "I have backups" into "I can restore":

• List the contents (does it include what you think it includes?).
• Test the compressed layer (does it decompress?).
• Extract to a clean directory and spot-check key files.

warning

Extraction can overwrite files. Always restore into an empty directory first (for example /tmp/restore-test/). Only copy into place after validation.

Quick lab

This lab demonstrates the shape of a backup/verify cycle using tar.gz and gzip.

Create a backup directory:

create-backup-directory.sh

sudo mkdir -p /backups

Archive WordPress files with sensible excludes:

archive-wordpress-files-tar-gzip.sh

sudo tar -C /var/www/html \
  --exclude='wp-content/cache' \
  --exclude='wp-content/*/cache' \
  -czvf "/backups/wp-files-$(date +%F).tar.gz" \
  .

Dump and compress the database (adjust credentials and DB name):

dump-and-compress-database-gzip.sh

mysqldump --single-transaction -u DB_USER -p DB_NAME \
  | gzip > "/backups/wp-db-$(date +%F).sql.gz"

Verify both artifacts:

verify-archives.sh

tar -tzf "/backups/wp-files-$(date +%F).tar.gz" >/dev/null
gzip -t "/backups/wp-db-$(date +%F).sql.gz"

Restore drill (extract to staging path):

restore-drill-extract-files.sh

sudo rm -rf /tmp/restore-test
sudo mkdir -p /tmp/restore-test
sudo tar -xzf "/backups/wp-files-$(date +%F).tar.gz" -C /tmp/restore-test

Cheat sheet

Task	Command
Create tar.gz (directory)	tar -C /path -czvf out.tar.gz .
List tar.gz contents	tar -tzf out.tar.gz
Extract tar.gz to target	tar -xzf out.tar.gz -C /tmp/restore-test
Compress a single file	gzip file.sql
Decompress to stdout	gunzip -c file.sql.gz > file.sql

Mini quiz

1. Why is tar used before compression for directory backups?

2. What is the risk of extracting an archive directly into /var/www/html?

3. When is .zip a better choice than .tar.gz?

4. What is the minimum restore test you should do after creating a backup?