Veritas File System 5.0 Administrator's Guide (September 2006)

to another, or relocate files by running file relocation commands. Having multiple
volumes lets you determine where files are located, which can improve
performance for applications that access specific types of files. DST functionality
is a separately licensed feature and is available with the VRTSfppm package.
See About Dynamic Storage Tiering” on page 135.
Veritas 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.
See Using Veritas File Systemon page 24.
VxFS provides the following performance enhancements:
Data synchronous I/O
Direct I/O and discovered direct I/O
Support for files and file systems up to 256 terabytes
Support for files up to 2 terabytes
Enhanced I/O performance
Caching advisories
Enhanced directory features
Explicit file alignment, extent size, and preallocation controls
Tunable I/O parameters
Tunable indirect data extent size
Integration with VxVM™
Support for large directories
Note: VxFS reduces the file lookup time in directories with an extremely large
number of files.
23Introducing Veritas File System
Veritas File System performance enhancements