What Data Should You Back Up

What Data Should You Back Up

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Not all data is equal. Backing up everything wastes storage and time; backing up too little risks losing critical information. Let's walk through a systematic approach to identifying what to protect.

Tier 1: Critical Data (Must Back Up)

These are the files and systems your business cannot operate without. Losing them means immediate downtime and potential closure:

• Customer databases — CRM data, customer contact info, order history.
• Financial records — Accounting databases, invoices, tax records, payroll data.
• Business documents — Contracts, legal agreements, employee records, intellectual property.
• Application data — Website content, application databases, configuration files.
• Email and communications — Email archives, chat logs, voicemails (often required for compliance).

Tier 2: Important Data (Should Back Up)

Losing these causes significant disruption but may not halt operations immediately:

• Project files — Source code repositories, design files, marketing materials.
• System configurations — Server configs, network device configs, firewall rules. Recreating these from scratch takes hours.
• Employee workstations — Documents, spreadsheets, presentations on local drives that aren't on the server.

Tier 3: Replaceable Data (Optional)

These can be re-downloaded or regenerated, but backing them up saves time:

• Software installers and packages (can re-download).
• Operating system images (can reinstall, though backups save hours).
• Cache and temporary files (skip entirely — they waste backup space).

How to Audit Your Data (Step by Step)

1. Inventory your servers: SSH into each and list key directories: ls -la /home /var/www /opt /etc.
2. Ask department heads: "If you lost everything on your computer today, what would you need back within 24 hours?" Their answers define Tier 1.
3. Check application data: For web apps, identify the database and uploaded files directories. For Docker, back up volumes with docker run --rm -v myvolume:/data -v /backup:/backup alpine tar czf /backup/myvolume.tar.gz /data.
4. Export cloud data: Google Workspace data can be exported via Google Takeout. Microsoft 365 via the Compliance Center's export tools.
5. Document your backup scope: Create a spreadsheet listing each data source, its location, its tier, and its backup schedule.

Don't Forget These Easily Overlooked Items

• SSL certificates and private keys — If lost, your website goes down and you must re-issue certificates.
• API keys and credentials — Stored in password managers like Bitwarden or Vault, back up the vault itself.
• DNS zone configurations — If you self-host DNS, losing zone files can take your domain offline.
• Calendar and contacts — Often synced but not backed up separately. Export regularly as .ics/.vcf.
• Database transaction logs — For databases, back up not just the data files but also WAL/binlog files for point-in-time recovery.

Key Takeaways

• Tier your data: critical (must), important (should), replaceable (optional). This saves storage and ensures the right data is protected first.
• Don't forget system configs, certificates, and credentials — they're critical but often overlooked.
• Conduct a data audit with department heads to identify what truly matters.
• Document your backup scope in a spreadsheet — it's your recovery roadmap when things go wrong.