VERITAS File System 4.1 Administrator's Guide

Chapter 10 151
10 Quality of Storage Service
The VERITAS File System allows you to create a file system that spans multiple volumes
,known as a multi-volume file system. The component volumes compose a volume set. See
“Quality of Storage Service” on page 151. On top of this basic capability is a set of services
known as Quality of Storage Service (QoSS).
Using different volumes you can enhance the performance of applications, that access specific
types of files, using different volumes and managing where the types of files are located.For
example, if you have files that are infrequently accessed, you can place them on slower media
that is relatively inexpensive, but which has a slower access time.
You can configure policies that automatically relocate files from one volume to another, or you
can relocate files by running file relocation commands.The QoSS has two parts:
• Relocation policies: Policies that you configure to determine which files to move to a
different component volume.
• File relocation: The fssweep utility recursively examines a multi-volume file system by
searching for files that match configured relocation policies. After searching a file system,
fssweep passes information about files that match policies to the fsmove utility. The
fsmove utility reads a list of file names and locations that fssweep has created and
relocates files based on that relocation list.
NOTE VERITAS Quality of Storage Service is a licensed feature.You must purchase a
separate license key to enable the QoSS feature.See the VERITAS File System
Release Notes for current product information.