Hi, I have been working recently on support for asynchronous file i/o in asio library in linux. Perhaps some of my code will interest you. The interface allows for doing read, write and fsync/fdatasync operations. The implementation uses either POSIX AIO or linux-native libaio (this may be currently switched by #define ASIO_USE_LIBAIO). I have based the initial work on patch brought by Felipe Magno de Almeida in 2005 (http://lists.boost.org/Archives/boost/2005/09 /93068.php). As you may realize by studying my modifications of task_io_service, the file i/o operations are unable to coexist with operations of other kind within single io_service. I did not have time to test it thoroughly, but basic tests pass. The patch is created against 1_45_0 version, however everything works well when applied to 1_46_1. The tarball contains also a simple example file and a script that compiles it. I will be pleased to receive any feedback. -- Best regards, Kamil Nowosad