Manual:$wgFileCacheDirectory/zh

详情
If you switch on server-side file caching, 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:

...but you can specify this absolute path in relation to other directory path variables, e.g.:

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

参见

 * - 启用文件缓存
 * - Depth of the subdirectory hierarchy to be created under $wgFileCacheDirectory.
 * - Depth of the subdirectory hierarchy to be created under $wgFileCacheDirectory.