Description: The policy that determines how transaction log file entries are written to disk. This policy can affect transaction performance. (Note: To be transactionally safe, the Direct-Write policy may require additional OS or environment changes on some Windows systems.) WebLogic Server supports the following policies: Cache-Flush. Flushes operating system and on-disk caches after each write. Direct-Write. Tells the operating system to write directly to disk with each write. Direct-Write performs better than Cache-Flush and is available on Windows, HP-UX, and Solaris. If Direct-Write is not supported on the host platform, the policy becomes Cache-Flush and a log message is printed. Note: On Windows, unlike Solaris and HP, the 'Direct-Write' policy may leave transaction data in the on-disk cache without writing it to disk immediately. This is not transactionally safe because a power failure can cause loss of on-disk cache data. For transactionally safe writes using 'Direct-Write' on Windows, either disable all write caching for the disk (enabled by default), or use a disk with a battery-backed cache. The on-disk cache for a hard-drive on Windows can be disabled through system administration: Control-Panel -> System -> Hardware-tab -> Device-Manager-button -> Disk-Drives -> name-of-drive -> Policies-tab -> 'Enable write caching on the disk' check-box. Some file systems do not allow this value to be changed. For example, a RAID system that has a reliable cache.