1. A computer-implemented method for updating references to a migrated object that has moved from a source partition server to a target partition server in a distributed file system having a plurality of partition servers, wherein each object has an associated parent object and each partition server owns a subset of objects of the file system, comprising: maintaining in each parent object a set of forward pointers that reference one or more child objects of the parent object; maintaining in the migrated object a set of back pointers that reference one or more parent objects having forward pointers to the migrated object; transmitting an update request to each partition server that owns a parent object of the migrated object; and updating the forward pointers in each parent object in response to the update request.