SaveChm: The Complete Guide to Preserving CHM Files Safely

SaveChm Tips: Best Practices for Archiving Compiled HTML Help

1. Prepare your CHM files

• Organize: Keep source files and final .chm in a consistent folder structure (e.g., /source, /build, /archive).
• Version: Include version numbers or dates in filenames (e.g., help_v1.2_2026-02-06.chm).

2. Verify integrity before archiving

• Open-check: Open each .chm to ensure all content, images, and links render correctly.
• Link test: Click through a representative set of pages and external links.
• Spell/format check: Run a quick spellcheck and visual pass to catch obvious issues.

3. Add metadata and documentation

• README: Include a short README with build steps, required tools (compiler versions), and source locations.
• Changelog: Add a changelog summarizing edits between versions.
• Checksums: Create and store a checksum (SHA256) for each .chm file.

4. Choose archive formats and compression

• Container: Store .chm alongside source in a compressed container (ZIP or 7z).
• Compression: Use lossless compression; 7z typically yields smaller sizes.
• Structure: Preserve directory structure inside the archive for reproducibility.

5. Preserve build environment

• Tool versions: Record compiler/toolchain versions (e.g., HTML Help Workshop version).
• Scripts: Include build scripts and any configuration files used to generate the CHM.
• Virtual image (optional): For long-term reproducibility, include a small VM/container image or a Dockerfile capturing the build environment.

6. Storage strategy

• Multiple copies: Keep at least three copies: local, offsite/cloud, and archival cold storage.
• Redundancy: Use different storage providers/formats to reduce correlated risk.
• Retention policy: Define how long to keep versions and when to prune.

7. Security and access control

• Permissions: Restrict write access to archive locations; use read-only where possible.
• Encryption: Encrypt archives containing sensitive content before uploading to cloud storage.
• Audit logs: Track who archived or restored files and when.

8. Automation and CI/CD

• Automate: Integrate CHM builds and archiving into CI pipelines to reduce human error.
• Naming: Automate consistent naming (version, date, commit hash).
• Notifications: Add alerts for failed builds or archive verifications.

9. Regular verification

• Periodic checks: Recompute checksums and attempt restores on a schedule (e.g., quarterly).
• Integrity monitoring: Use automated tools to detect bit rot or corrupt archives.

10. Recovery procedures

• Restore test: Periodically perform a full restore to verify archive usability.
• Documentation: Keep step-by-step restore instructions with contact points for issues.

Table: Recommended archive layout

Follow these practices to ensure your CHM files remain accessible, verifiable, and reproducible over time.