A method is used in managing truncation of files of file systems. A request is received to delete a portion of a file of a file system. A set of extents associated with the portion of the file is determined where the file has been identified for deletion. A replica of the set of extents is created. The replica represents a state of the set of extents at a particular prior point in time. The portion of the file is deleted by updating metadata of the file. The replica is asynchronously deleted in background.