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

Warning: Multiple tagging should be used carefully.
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.
See the Veritas Volume Manager Administrator's Guide.
How SmartTier works
SmartTier is a VxFS feature that enables you to allocate file storage space from
different storage tiers according to rules you create. SmartTier provides a more
flexible alternative compared to current approaches for tiered storage. Static
storage tiering involves a manual one-time assignment of application files to a
storage class, which is inflexible over a long term. Hierarchical Storage
Management solutions typically require files to be migrated back into a file system
name space before an application access request can be fulfilled, leading to latency
and run-time overhead. In contrast, SmartTier allows organizations to:
■ Optimize storage assets by dynamically moving a file to its optimal storage
tier as the value of the file changes over time
■ Automate the movement of data between storage tiers without changing the
way users or applications access the files
■ Migrate data automatically based on policies set up by administrators,
eliminating operational requirements for tiered storage and downtime
commonly associated with data movement
SmartTier leverages two key technologies included with Veritas Storage
Foundation: support for multi-volume file systems and automatic policy-based
placement of files within the storage managed by a file system. A multi-volume
file system occupies two or more virtual storage volumes and thereby enables a
single file system to span across multiple, possibly heterogeneous, physical storage
devices. For example the first volume could reside on EMC Symmetrix DMX
spindles, and the second volume could reside on EMC CLARiiON spindles. By
presenting a single name space, multi-volumes are transparent to users and
applications. This multi-volume file system remains aware of each volume’s
identity, making it possible to control the locations at which individual files are
stored. When combined with the automatic policy-based placement of files, the
multi-volume file system provides an ideal storage tiering facility, which moves
data automatically without any downtime requirements for applications and users
alike.
Understanding storage tiering with SmartTier
How SmartTier works
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