What are Synchronous and Asynchronous Writes?
If a file is open for writing and data is being written to a file, the data is accumulated in buffers and periodically written to disk. When an end-of-file condition occurs and the file is to be closed, any remaining buffer contents are written to the disk, the inode is updated with file size and block pointer information, and the file system’s list of free disk blocks is updated. To ensure maximum protection of file system integrity, these operations are handled in a specific sequence that minimizes the risk of file system corruption on the disk if a system crash or power failure occurs while writing to the disk. This sequential update process is called is called synchronous writing. HP-UX file systems store free space lists, blocks, inodes, and other file components at random and widely separate locations on disk devices. This means that writing file information blocks in a particular sequence requires additional time to move to the desired location on the disk before performing the
