Veritas Storage Foundation 5.1 SP1: Storage and Availability Management for Oracle (5900-1504, April 2011)

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.
This feature is available only on file systems meeting the following requirements:
■ The minimum disk group version is 140.
■ The minimum file system layout version is 7 for file level SmartTier.
■ The minimum file system layout version is 8 for sub-file level SmartTier.
To convert your existing VxFS system to a VxFS multi-volume file system, you
must convert a single volume to a volume set.
For procedures, see the Veritas Storage Foundation Advanced Features Guide.
The VxFS volume administration utility (fsvoladm utility) can be used to administer
VxFS volumes. The fsvoladm utility performs administrative tasks, such as adding,
removing, resizing, encapsulating volumes, and setting, clearing, or querying
flags on volumes in a specified Veritas File System.
See the fsvoladm (1M) manual page for additional information about using this
utility.
About VxVM volume sets
Volume sets allow several volumes to be represented by a single logical object.
Volume sets cannot be empty. All I/O from and to the underlying volumes is
directed via the I/O interfaces of the volume set. The volume set feature supports
the multi-volume enhancement to Veritas File System (VxFS). This feature allows
file systems to make best use of the different performance and availability
characteristics of the underlying volumes. For example, file system metadata
could be stored on volumes with higher redundancy, and user data on volumes
with better performance.
See the Veritas Volume Manager Administrator's Guide.
About volume tags
You make a VxVM volume part of a placement class by associating a volume tag
with it. For file placement purposes, VxFS treats all of the volumes in a placement
class as equivalent, and balances space allocation across them. A volume may
have more than one tag associated with it. If a volume has multiple tags, the
volume belongs to multiple placement classes and is subject to allocation and
relocation policies that relate to any of the placement classes.
235Understanding storage tiering with SmartTier
SmartTier building blocks