Advanced Configuration for the WordPress WP Super Cache Plugin
The popular WordPress plugin — WP Super Cache — requires advanced configuration. That is, this isn’t a “set it and forget it” type of plugin. To use this WordPress plugin, you need to perform additional configurations.
The WP Super Cache plugin is a must for every WordPress site because it helps shorten the time it takes for your site visitors to pull up the site in their browsers by serving static HTML files rather than dynamically generating the WordPress pages they see each time.
For the best performance results with this plugin, make sure that PHP Safe mode is disabled on your web server, and that the Apache modules mod_mime and mod_rewrite are installed. If you are unsure whether Safe mode is disabled, or if your server already has these Apache modules, check with your web hosting provider.
After installing and activating WP Super Cache, the plugin needs to be configured to enable caching on your site:
Click the Plugin Admin Page link to visit the WP Super Cache Plugin Settings page in your Dashboard.
After you click the Plugin Admin Page link to access the Plugin Settings page, WP Super Cache attempts to make certain changes to files on your web server. Depending on your server settings and file permissions, you may need to do these tasks manually:
Create a new advanced-cache.php file: If you get the message that says, “Warning! /wp-content/advanced-cache.php does not exist or cannot be updated,” you need to make adjustments to the folder permissions on your web server so that the plugin can create the file:
Via FTP, navigate to your blog’s root directory (the directory that has wp-admin and wp-content).
Make the wp-content directory writable by changing the directory permissions to 777.
In your WordPress Dashboard, refresh the WP Super Cache Settings page.
Make sure that you change the /wp-content folder permissions back to 755 so that the directory is not publically writable.
Configure the wp-config.php file: You may get the message, “Error: WP_CACHE is not enabled in your wp-config.php file.”
To fix this, use your FTP software to edit the wp-config.php file you used when you set up your WordPress blog. Add the following line:
Save the file and upload it to the server, overwriting the old file. After you refresh your WP Super Cache Settings page again, you should no longer see the error message.
Enable caching: For basic use of WP Super Cache, select the Caching On radio button under the Caching heading on the WP Super Cache Settings page to enable caching on your site and then click the Update Status button.
Modify the .htaccess file: You may get a message telling you that your .htaccess file needs to be updated.Modify permissions for the .htaccess file.
To resolve this, modify the permissions of your .htaccess file to writable (777). Be sure to go back to the web server directory in your FTP program and reset the file permissions on your .htaccess file to its previous permissions (probably 755 or 644) to retain security on that file.
Enable Super Cache Compression: On the WP Super Cache Settings page, click the Advanced tab to load the advanced settings in your browser window. Click the box to the left of the Compress page so they’re served more quickly to visitors to enable compression.