HP StorageWorks XP Tiered Storage Manager Server Installation and Configuration Guide (December 2005)

Overview of Tiered Storage Manager 10
Figure 1-1 Data Lifecycle Management
1-1-3 Improving Efficiency
Tiered Storage Manager allows you to improve the efficiency of your storage management in the following
ways:
Reducing total cost of ownership. If you migrate data using data lifecycle management, you improve
efficiency and reduce the total cost of ownership (TCO) of your storage subsystems.
NOTE: You cannot use Tiered Storage Manager to migrate data to a tape device.
Maximizing performance. You can use Tiered Storage Manager to do a performance analysis. This can
find bottlenecks where there are multiple volumes with a high access frequency in the same array group
in the same storage subsystem, which can impact performance. Distributing that access load across
different array groups or subsystems can greatly improve performance.
Managing changes to the storage environment. If you are introducing a new storage subsystem, you can
migrate data with a high usage frequency to high-performance storage. If you are discarding an obsolete
subsystem, you can migrate the data to different subsystems. If you are re-arranging storage, data
migration makes the process much easier.
1-2 Overview of Data Migration
1-2-1 The Data Migration Process
You can migrate data between storage subsystems that are within the same migration scope. Data can be
copied within a subsystem, between a subsystem and an external subsystem, or between external
subsystems. Eligible data is migrated without the user being aware of the change in LDEV number, because
Tiered Storage Manager changes the LDEV number automatically. This prevents interruption of an application
service. Data is migrated in volumes.
Data Migration consists of the following steps:
1. A migration task is created, and the migration target volume is reserved, so it is no longer accessible from
the host.
2. Data is copied from the source volume to the target volume.
3. The LDEV number of the source volume is reserved, and then it is switched between the source volume
and the target volume. The target volume is reserved when the switch is made, so it is no longer
accessible from the host.