10 DS8000 Series: Concepts and Architecture
IBM TotalStorage Global Mirror (Asynchronous PPRC)
Global Mirror copying provides a two-site extended distance remote mirroring function for
z/OS and open systems servers. With Global Mirror, the data that the host writes to the
storage unit at the local site is asynchronously shadowed to the storage unit at the remote
site. A consistent copy of the data is then automatically maintained on the storage unit at the
remote site.This two-site data mirroring function is designed to provide a high performance,
cost effective, global distance data replication and disaster recovery solution.
IBM TotalStorage z/OS Global Mirror (Extended Remote Copy XRC)
z/OS Global Mirror is a remote data mirroring function available for the z/OS and OS/390
operating systems. It maintains a copy of the data asynchronously at a remote location over
unlimited distances. z/OS Global Mirror is well suited for large zSeries server workloads and
can be used for business continuance solutions, workload movement, and data migration.
IBM TotalStorage z/OS Metro/Global Mirror
This mirroring capability uses z/OS Global Mirror to mirror primary site data to a location that
is a long distance away and also uses Metro Mirror to mirror primary site data to a location
within the metropolitan area. This enables a z/OS three-site high availability and disaster
recovery solution for even greater protection from unplanned outages.
Three-site solution
A combination of Global Mirror and Global Copy, called Metro/Global Copy is available on the
ESS 750 and ESS 800. It is a three site approach that was previously called Asynchronous
Cascading PPRC. You first copy your data synchronously to an intermediate site and from
there you go asynchronously to a more distant site.
For more information about Copy Services see Chapter 7, “Copy Services” on page 115.
1.2.6 Interoperability
As we mentioned before, the DS8000 supports a broad range of server environments. But
there is another big advantage regarding interoperability. The DS8000 Remote Mirror and
Copy functions can interoperate between the DS8000, the DS6000, and ESS Models
750/800/800Turbo. This offers a dramatically increased flexibility in developing mirroring and
remote copy solutions, and also the opportunity to deploy business continuity solutions at
lower costs than have been previously available.
1.2.7 Service and setup
The installation of the DS8000 will be performed by IBM in accordance to the installation
procedure for this machine. The customer’s responsibility is the installation planning, the
retrieval and installation of feature activation codes, and the logical configuration planning
and application. This hasn’t changed in regard to the previous ESS model.
For maintenance and service operations, the Storage Hardware Management Console
(S-HMC) is the focal point. The management console is a dedicated workstation that is
Note: Metro/Global Copy is not available on the DS8000. According to the announcement
letter IBM has issued a Statement of General Direction:
IBM intends to offer a long-distance business continuance solution across three sites
allowing for recovery from the secondary or tertiary site with full data consistency.
