In V11 and later, support for direct I/O has been enabled on Linux systems. A value of 512-bytes is used for size and alignment for direct I/O.
This feature supports both c-tree data and index files, as well as transaction logs. Configuration options are provided for both.
Note: This feature requires Linux kernel version 2.6 or later, c-treeACE Server logs an error message to CTSTATUS.FCS if these options are used on pre-2.6 Linux kernel systems. The error messages are:
The UNBUFFERED_IO option requires Linux kernel version 2.6 or later
The UNBUFFERED_LOG_IO option requires Linux kernel version 2.6 or later