Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

Supported SmartTier document type definitions
Table 25-1 describes which releases of Veritas File System (VxFS) support specific
SmartTier document type definitions (DTDs).
Table 25-1
Supported SmartTier document type definitions
DTD Version
VxFS Version 1.11.0
Not supportedSupported5.0
SupportedSupported5.1
SupportedSupported5.1 SP1
Placement classes
A placement class is a SmartTier attribute of a given volume in a volume set of a
multi-volume file system. This attribute is a character string, and is known as a
volume tag. A volume can have different tags, one of which can be the placement
class. The placement class tag makes a volume distinguishable by SmartTier.
Volume tags are organized as hierarchical name spaces in which periods separate
the levels of the hierarchy . By convention, the uppermost level in the volume tag
hierarchy denotes the Storage Foundation component or application that uses a
tag, and the second level denotes the tag’s purpose. SmartTier recognizes volume
tags of the form vxfs.placement_class.class_name. The prefix vxfs identifies
a tag as being associated with VxFS. The placement_class string identifies the
tag as a file placement class that SmartTier uses. The class_name string represents
the name of the file placement class to which the tagged volume belongs. For
example, a volume with the tag vxfs.placement_class.tier1 belongs to placement
class tier1. Administrators use the vxassistvxvoladm command to associate
tags with volumes.
See the vxassistvxvoladm(1M) manual page.
VxFS policy rules specify file placement in terms of placement classes rather than
in terms of individual volumes. All volumes that belong to a particular placement
class are interchangeable with respect to file creation and relocation operations.
Specifying file placement in terms of placement classes rather than in terms of
specific volumes simplifies the administration of multi-tier storage.
The administration of multi-tier storage is simplified in the following ways:
341Administering SmartTier
Supported SmartTier document type definitions