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Disk Usage

Running out of disk space is one of the most common causes of WordPress site failures — database writes stop, backups fail, and log files can no longer rotate. WPHammer monitors disk usage at both the server level and the individual site level to give you early warning before space runs out.

Server-level disk usage

Each server tracks two values collected via SSH:

  • Total disk space — the total capacity of the root filesystem in kilobytes
  • Used disk space — the amount currently consumed

From these, WPHammer calculates a usage percentage. This value appears on the server list, the server detail page, and the dashboard health view.

Site-level disk usage

In addition to the overall server disk, WPHammer collects disk usage for each individual site. This tells you which sites are consuming the most space — useful for identifying sites with large media libraries, unmanaged backup files, or bloated log directories.

Site disk usage is collected alongside the server disk check, using the site's root directory as the measurement point.

How collection works

Disk usage is collected via SSH commands executed against the server. The collection runs as a scheduled background job that:

  1. Connects to the server over SSH
  2. Reads the overall filesystem usage
  3. Measures the disk footprint of each site's directory
  4. Stores the readings with a timestamp

The timestamp of the last check is recorded so you can see how fresh the data is. If a server is unreachable via SSH, the collection is skipped and the previous readings remain until the next successful check.

Thresholds

Disk usage is evaluated as part of the server health metric system. The thresholds work the same way as other metrics:

  • Ok — disk usage is within a comfortable range
  • Warning — usage is elevated and should be monitored. Consider cleaning up old backups, logs, or unused files.
  • Critical — the server is at risk of running out of space. Immediate action is recommended.

Common causes of high disk usage

  • Unmanaged backups — old backup files accumulating on the server instead of being offloaded to remote storage
  • WordPress uploads — large media libraries, especially when original files are kept alongside generated thumbnails
  • Log files — application, web server, or error logs that are not being rotated or truncated
  • Core dumps or temp files — system-level artifacts from crashed processes
  • Unused staging sites — staging copies that were created but never cleaned up

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