Abstract: The invention concerns reliable writing of database log data, In particular, the invention concerns a computer system, methods and software to enable database log data to be written to recoverable storage in a reliable way. There is provided a computer system (100) for writing database log data to recoverable storage (60) comprising a durable database management system (DBMS) (40); and a hypervisor (80) or kernel 81 that enables communications between the recoverable storage device driver (52) and a recoverable storage device (60) to write the log data written to the non recoverable storage (92) and (42) to the recoverable storage device (60) asynchronously to the continued writing of log data to the non-recoverable storage (42) and (92). This allows the DBMS (40) to ensure recoverability and serializability and still allowing logs to be written asynchronously removing a performance bottleneck for the DBMS.