Computer Drive User Manual

4 IBM System Storage DS6000 Series: Copy Services with IBM System z
1.1 Introduction to Copy Services
We briefly describe each function of the Copy Services in this section. Copy Services are a
collection of functions that provide for Disaster Recovery, data migration, and data duplication
functions. There are two primary types of Copy Services functions:
Point-in-Time Copy and
Remote Mirror and Copy. Generally, the Point-in-Time Copy function is used for data
duplication and the Remote Mirror and Copy function is used for data migration and Disaster
Recovery.
With the Copy Services functions, you can create backup data with little or no disruption to
your application, and you can back up your application data to the remote site for uses such
as Disaster Recovery.
Copy Services run on the DS6000 Storage Unit and support open systems and System z
environments. These functions are also supported on the DS8000 series and the previous
generation of storage systems, the IBM TotalStorage Enterprise Storage Server (ESS).
Many design characteristics of the DS6000 and data copying and mirroring capabilities of the
Copy Services features contribute to the protection of data, 24 hours a day and seven days a
week. The licensed features included in Copy Services are the following:
򐂰 FlashCopy, which is a Point-in-Time Copy function
򐂰 Remote Mirror and Copy functions, previously known as Peer-to-Peer Remote Copy or
PPRC, which include:
– IBM System Storage Metro Mirror, previously known as synchronous PPRC
– IBM System Storage Global Copy, previously known as PPRC Extended Distance
– IBM System Storage Global Mirror, previously known as Asynchronous PPRC
򐂰 z/OS Global Mirror, previously known as Extended Remote Copy (XRC)
򐂰 z/OS Global Mirror and Metro Mirror across three sites. In this environment the DS6000
can only operate as a secondary system.
We explain these functions in more detail in the next section.
You can manage the Copy Services functions through a command-line interface (DS CLI)
and a new Web-based interface (DS Storage Manager). You can also manage the Copy
Services functions through the open application programming interface (DS Open API).
When you manage the Copy Services through these interfaces, these interfaces invoke Copy
Services functions via the Ethernet network. In System z environments, you can invoke the
Copy Service functions by TSO commands, ICKDSF, the DFSMSdss™ utility, and so on.
We explain these interfaces in Part 2, “Interfaces” on page 15.
1.1.1 Point-in-Time Copy (FlashCopy)
The Point-in-Time Copy feature, which includes FlashCopy, enables you to create full volume
copies of data in a Storage Unit. To use it, you must purchase the Point-in-Time Copy
License feature code #5200 PTC for the required DS6800 storage server machine type 1750.
When you set up a FlashCopy operation, a relationship is established between the source
and target volumes, and a bitmap of the source volume is created. Once this relationship and
bitmap are created, the target volume can be accessed as though all the data had been
physically copied. While a relationship between the source and target volume exists,
optionally, a background process copies the tracks from the source to the target volume.