Monitor storage usage

POM Cache stores generated HTML and progressive JSON on disk. Its storage footprint grows with the number of distinct cacheable public representations, not simply with the number of WordPress posts.

Establish a baseline

Open Settings → POM Cache → General and record:

• the file count and size under Cache Contents;
• the file count and size under Progressive JSON Cache Contents;
• the date, site, environment, and traffic pattern represented by the sample.

Repeat the measurement after a normal traffic period. On multisite, collect the values for each site you operate; the settings screen reports only the current site's tree.

What creates additional files

HTML storage usually grows as visitors reach additional cacheable paths. Progressive JSON can add variants for combinations such as:

• archive post type;
• language or locale;
• page or result batch;
• public filters and faceted-search state;
• rendering context encoded into the cache path.

Distinct hosts or multisite sites must remain isolated. Old slugs, retired languages, and changed filter structures can leave files that are no longer requested until the relevant store is cleared.

There is no age-based garbage collector

POM Cache does not automatically delete a file just because it is old, and it does not preload all routes after deletion. Freshness is maintained through configured invalidation and explicit clearing.

Plan storage capacity accordingly. A stable count after representative traffic is usually more informative than a single absolute number. Continuous growth without a matching expansion in public content or valid URL variants needs investigation.

Investigate unexpected growth

1. Determine whether HTML or JSON accounts for the increase.
2. Check whether the site recently added languages, archives, filters, pagination, or permalink variants.
3. Look for multiple public URLs that render the same content because of inconsistent canonicalization.
4. Confirm that only known tracking parameters are removed and that meaningful query parameters are not accidentally converted into cache variants.
5. Review invalidation switches for edited content and taxonomies.
6. Check whether a deployment changed the cache location and left an obsolete tree behind.
7. Clear only the affected current-site store, exercise representative routes, and measure its new steady state.

Do not solve unexplained growth by scheduling indiscriminate recursive deletion. That can conceal a URL-design or invalidation problem and can be unsafe on multisite.

Capacity and alerting

POM Cache does not send disk-space alerts. Use hosting or operating-system monitoring for:

• filesystem free space and inode availability;
• growth rate of the configured cache root;
• write errors or permission failures;
• unusually large individual JSON responses;
• CDN origin-request changes following cache deletion.

Set alerts with enough headroom to investigate safely. Cache generation needs temporary space because files are written through a temporary artifact and then moved into place.

Reducing storage safely

Start with the appropriate POM Cache delete action for the current site. The next eligible request recreates only the content that is actually requested. If old files exist outside the configured current tree, first prove that neither the runtime nor web-server rules reference them. Back up the path, validate its exact scope, and use your hosting tools to remove it; the POM Cache interface intentionally avoids broad external-directory cleanup.