Manual:$wgFileCacheDirectory

File Cache: $wgFileCacheDirectory
Directory where the cached page will be saved when using server-side caching.
Introduced in version:	pre 1.1.0
Removed in version:	still in use
Allowed values:	absolute path
Default value:	"{$wgUploadDirectory}/cache" (Note: The default value of this variable depends on other variables, such as the values set in Setup.php, after LocalSettings.php is executed)

Other settings: Alphabetical | By Function

Details

This is the directory where cached page will be saved when using file caching.

If you switch on server-side file caching $wgUseFileCache = true;, then you can use this variable to specify where the cached pages will be saved on your server filesystem.

It's an absolute path, so you could specify somewhere under /tmp for example:

$wgFileCacheDirectory = "/tmp/yourcache";

...but you can specify relative to other directory path variables...
...e.g. up to 1.15.*:

$wgFileCacheDirectory = "{$wgUploadDirectory}/cache";

...e.g. since 1.16.*:

$wgFileCacheDirectory = "{$wgCacheDirectory}/html";

This specifies a "cache" directory under the image uploads directory (normally called "images"). This is the default setting in fact.

In some versions, you must create the directory and ensure it is writeable (by the php user). This is even true if you leave it as the default (You must create the "images/cache" directory). It appears that in at least 1.15+ the directory will be created for you if it can be.

If you are hosting multiple Wikis from a shared source you must ensure each has its own cache directory to avoid miss-serving pages with the same name (the Main_Page, for example).

See also

• Manual:$wgFileCacheDepth - Depth of the subdirectory hierarchy to be created under $wgFileCacheDirectory.
• Manual:File cache
• Manual:$wgCacheDirectory