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

Dynamic Storage Tiering

This chapter includes the following topics:

■ About Dynamic Storage Tiering

■ Placement classes

■ Administering placement policies

■ File placement policy grammar

■ File placement policy rules

■ Calculating I/O temperature and access temperature

■ Multiple criteria in file placement policy rule statements

■ File placement policy rule and statement ordering

■ File placement policies and extending files

About Dynamic Storage Tiering

VxFS uses multi-tier online storage via the Dynamic Storage Tiering (DST) feature,

which functions on top of multi-volume file systems. Multi-volume file systems

are file systems that occupy two or more virtual volumes. The collection of volumes

is known as a volume set, and is made up of disks or disk array LUNs belonging

to a single Veritas Volume Manager (VxVM) disk group. A multi-volume file system

presents a single name space, making the existence of multiple volumes

transparent to users and applications. Each volume retains a separate identity

for administrative purposes, making it possible to control the locations to which

individual files are directed.

Chapter