Application Interface

The VERITAS File System (VxFS) provides enhancements that can be used by applications that require certain performance features. This chapter describes cache advisories and provides information about fixed extent sizes and reservation of space for a file.

If you are writing applications, you can optimize them for use with the VxFS. To optimize VxFS for use with applications, see VxFS Performance: Creating, Mounting, and Tuning File Systems.

The following topics are covered in this chapter:

• Cache Advisories
• Direct I/O
• Unbuffered I/O
• Discovered Direct I/O
• Data Synchronous I/O
• Other Advisories
• Extent Information
• Space Reservation
• Fixed Extent Sizes
• Freeze and Thaw
• Get I/O Parameters ioctl
• Named Data Streams
• Named Data Streams Programmatic Interface
• Listing Named Data Streams
• Namespace for Named Data Streams
• Behavior Changes in Other System Calls