Veritas™ File System 5.0.1 Administrator's Guide

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 by way of 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. A volume set 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.

See “About multi-volume support” on page 122.

Chapter