/**
* File backend structure configuration.
+ *
* This is an array of file backend configuration arrays.
* Each backend configuration has the following parameters:
- * - 'name' : A unique name for the backend
- * - 'class' : The file backend class to use
- * - 'wikiId' : A unique string that identifies the wiki (container prefix)
- * - 'lockManager' : The name of a lock manager (see $wgLockManagers)
- *
- * Additional parameters are specific to the class used.
+ * - 'name' : A unique name for the backend
+ * - 'class' : The file backend class to use
+ * - 'wikiId' : A unique string that identifies the wiki (container prefix)
+ * - 'lockManager' : The name of a lock manager (see $wgLockManagers)
+ *
+ * See FileBackend::__construct() for more details.
+ * Additional parameters are specific to the file backend class used.
+ * These settings should be global to all wikis when possible.
+ *
+ * There are two particularly important aspects about each backend:
+ * - a) Whether it is fully qualified or wiki-relative.
+ * By default, the paths of files are relative to the current wiki,
+ * which works via prefixing them with the current wiki ID when accessed.
+ * Setting 'wikiId' forces the backend to be fully qualified by prefixing
+ * all paths with the specified value instead. This can be useful if
+ * multiple wikis need to share the same data. Note that 'name' is *not*
+ * part of any prefix and thus should not be relied upon for namespacing.
+ * - b) Whether it is only defined for some wikis or is defined on all
+ * wikis in the wiki farm. Defining a backend globally is useful
+ * if multiple wikis need to share the same data.
+ * One should be aware of these aspects when configuring a backend for use with
+ * any basic feature or plugin. For example, suppose an extension stores data for
+ * different wikis in different directories and sometimes needs to access data from
+ * a foreign wiki's directory in order to render a page on given wiki. The extension
+ * would need a fully qualified backend that is defined on all wikis in the wiki farm.
*/
$wgFileBackends = array();
* This should consist of alphanumberic, '-', and '_' characters.
* This name should not be changed after use.
* - wikiId : Prefix to container names that is unique to this wiki.
+ * If not provided, this defaults to the current wiki ID.
* It should only consist of alphanumberic, '-', and '_' characters.
* - lockManager : Registered name of a file lock manager to use.
* - fileJournal : File journal configuration; see FileJournal::factory().