IBM DS6000 Series manual Few larger volumes

15.1 Introduction

The term data migration has a very diverse scope. We use it here solely to describe the process of moving data from one type of storage to another, or to be exact, from one type of storage to a DS6000. In many cases, this process is not only comprised of the mere copying of the data, but also includes some kind of consolidation.

With our focus on storage, we distinguish three kinds of consolidation, also illustrated in Figure 15-1:

￿The consolidation of distributed, direct-attached storage to shared, SAN-attached disk storage

￿The consolidation of many small volumes into a few larger ones

￿The consolidation of several small storage systems into a few larger ones

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Figure 15-1 Different ways of consolidation

Very often, the goal of a consolidation effort is a combination of more than one of these types.

There are many different methods for data migration. To decide on what is best in your case, gather information about the following items:

￿The source and target storage make and type

￿The amount of data to be migrated

￿The amount of time available for the migration

￿The ability to connect both source and target storage at the same time

￿The availability of spare disk or tape capacity for temporary storage

￿The format of the data itself

￿The consolidation goals

￿Can the migration be disruptive, and for how long?

￿The distance between source and target

We describe the most common methods in the next section. Be aware that, in a heterogeneous IT environment, you will most likely have to choose more than one method.

290DS6000 Series: Concepts and Architecture