Data Type

Integer

Default Value

0

Description

This parameter provides additional options to the FMS file system. Most of these options may be used to debug your application when performing direct I/O.

The value of IWARN you specify is obtained by adding together the numeric value of each option you select. Because these numeric values are a power of 2, they have the effect of setting bits in IOWARN.

  • 0, No warning messages are printed. When performing direct I/O, FMS increases the transfer length if required.
  • +1, Stop FMS if a condition is found that violates the requirements for direct I/O. You must also select one of the warning message tests listed below: (+4), (+8), (+16).
  • +2, Do not increase the length of transfers, even if the requested length does not satisfy the conditions for direct I/O.
  • +4, Print a warning message containing "DIO" if the transfer length requested does not satisfy the conditions for direct I/O. Note that by default, FMS automatically increases the transfer length if required. However this may have undesirable side effects if insufficient space was allocated on disk or in memory.
  • +8, Print a warning message containing "DIO" if the starting disk address does not satisfy the conditions for direct I/O.
  • +16, Print a warning message containing "DIO" if the starting memory address does not satisfy the conditions for direct I/O.
  • +1024, Do not print properties of removable disks. This option is useful in Windows systems when the removable media is not present.

A typical use of this Parameter is as follows:

  1. Add the following two lines to the license file:

    IOTYPE=2
    IOWARN=28

  2. Run your application, directing the output to a file, myout.txt.

    ./myapp > myout.txt

  3. Search for warning messages:

    grep DIO myout.txt