UpdraftPlus has become one of the most trusted and widely used WordPress backup plugins, boasting a powerful set of features that ensure data security and integrity for websites of all sizes. Among its core capabilities lies the concept of incremental backups — a method that allows users to back up only the files that have changed since the last backup. Despite its critical importance, some users began to notice a disconcerting issue: UpdraftPlus wasn’t always detecting file changes accurately during incremental backups. This problem had the potential to lead to incomplete backups, putting websites at risk.
TL;DR
UpdraftPlus users recently encountered an issue where the plugin failed to detect certain file changes during incremental backups. This stemmed from inefficiencies in the way the plugin scanned for deltas — file differences. A new fix to the delta scan mechanism was introduced, significantly improving the detection rate and performance. With the updated algorithm, UpdraftPlus now ensures more reliable, efficient backups, making it safer for WordPress site owners.
The Problem with Incremental Backups: What Went Wrong
Incremental backups are designed to save time, storage, and bandwidth. Instead of copying every file on a website, the plugin looks for changes—also known as “deltas”—from the last backup and only stores those. In theory, this is both elegant and efficient. However, between updates and caching layers, more nuanced file modifications—especially in dynamic or plugin-generated content—began to slip past the detection system.
Root causes of the issue included:
- Lack of proper file hashing: UpdraftPlus initially relied too heavily on file timestamps and sizes to detect changes.
- Filesystem latency: In some hosting environments, delays in reflecting file changes caused the plugin to miss updated files during its scan.
- Inefficient scanning logic: The existing delta detection algorithm required full directory traversals and couldn’t differentiate minor edits efficiently.
The net effect? Important updates — especially to plugin files, theme files, or dynamically generated content — could go unrecorded. This introduced risks like incomplete backups upon restore or unnoticed data loss after a migration.
Community Feedback and Discovery of the Detection Bug
Website administrators, developers, and IT consultants started raising red flags in support forums and GitHub discussions. They encountered scenarios where:
- Manual edits to crucial PHP files weren’t included in the nightly backup
- Media uploads did not trigger a new incremental backup
- Database entries were updated correctly, but associated file changes were absent in the backup record
UpdraftPlus forum moderators confirmed that under specific server configurations, like those using object caching or networked file systems (e.g., NFS), the delta scan could fail to verify subtle file-level changes accurately. This pressure from the user base prompted a deep-dive audit into the delta scanning algorithm.
The Delta Scan Fix: A Technical Overhaul
To restore confidence and meet user expectations, the UpdraftPlus development team implemented a major update known as the “Delta Scan Fix.” This wasn’t just a patch — it was a rebuild of foundational logic in how the plugin analyses file changes.
Key improvements introduced in the update:
- Checksum-based change detection: Instead of relying solely on file modification times and sizes, the new algorithm uses checksums (specifically MD5 hashes) to validate whether a file has changed since the last backup.
- Optimized directory traversal: The restructured code performs asynchronous, memory-efficient scans that work well even on large media folders with thousands of files.
- Intelligent caching mechanisms: Using an internal cache system, the plugin now temporarily stores known file states to compare changes even more rapidly.
The checksum feature is particularly game-changing. By comparing cryptographic hash values instead of timestamps alone, UpdraftPlus can now detect even a single-character change in a code file, making backups significantly more dependable.
Efficiency Gains After the Fix
The delta scan fix didn’t just improve accuracy; it also produced measurable gains in performance. Users on managed WordPress hosts with limited I/O bandwidth noticed incremental backup processes running 25–40% faster post-update. Here’s how the performance was optimized:
- Less CPU strain due to minimized directory recursion
- Reduced database read/writes because of smarter checksum caching
- Lower disk I/O usage on shared hosting environments
Moreover, sites employing staging environments saw benefits during site cloning processes. The smarter delta detection cut down unnecessary duplication of unmodified media and theme files, speeding up both export and import sequences.
“This fix is a huge leap forward,” said one WordPress consultant during testing. “For clients with sites that receive minor daily tweaks, like updated blog posts or refreshed product images, this ensures every change is secured without bloating backup storage.”
User Action: What Site Owners Should Do
If you’re a website owner using UpdraftPlus, here’s how you can maximize the benefit from the most recent changes:
- Update the plugin: Ensure you are running the latest version of UpdraftPlus. The delta scan fix was implemented in version 2.23.10 and above.
- Review backup settings: Under “Settings ➝ Files,” enable file change detection using checksums if it’s not selected by default.
- Run a manual incremental backup: Test the updated algorithm by editing a file and checking if the change is logged in the backup history.
- Monitor backup logs: After each backup, review the log files to confirm that the correct number of files are being included.
In addition, advanced users can now utilize new filter hooks added in the update, which allow conditional logic for file inclusion during delta scans. This enhances extensibility for developers managing multiple client installations or large-scale content-driven sites.
Conclusion: A More Reliable Future for WordPress Backups
Backups are more than a convenience — they are a lifeline when things go wrong. The recent issues with UpdraftPlus incremental backups exposed a blind spot in a tool otherwise known for reliability. However, the prompt and transparent response from the development team showcases the plugin’s long-term commitment to user trust and data integrity.
With the delta scan fix in place, UpdraftPlus has not only regained its reputation for backup fidelity but has also enhanced efficiency in ways that will benefit millions of sites. Whether you’re backing up a personal blog or a mission-critical enterprise site, you can now do so with greater confidence and precision.
As always, regular monitoring and good backup hygiene are just as important as having a quality plugin. Keep your systems up to date, test your backups periodically, and take full advantage of the powerful new tools UpdraftPlus now provides.
