File System Performance Enhancements

Traditional file systems employ block-based allocation schemes that provide adequate random access and latency for small files, but which limit throughput for larger files. As a result, they are less than optimal for commercial environments.

VxFS addresses this file system performance issue through an alternative allocation method and increased user control over allocation, I/O, and caching policies. An overview of the VxFS allocation policy is provided in the section Extent-Based Allocation.

VxFS provides the following performance enhancements:

• Extent-based allocation
• Enhanced mount options
• Data synchronous I/O
• Direct I/O and discovered direct I/O
• Caching advisories
• Enhanced directory features
• Explicit file alignment, extent size, and preallocation controls
• Tunable I/O parameters
• Tunable indirect data extent size
• Integration with VERITAS Volume Manager^™ (VxVM^®)
• Support for improved database performance

The rest of this chapter, as well as VxFS Performance: Creating, Mounting, and Tuning File Systems and Application Interface provide details on many of these features.