IBM DS8000 manual Comparison of migration methods, Host operating system-based migration

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.

Note: When discussing disruptiveness, we don't consider any interruptions that may be caused by adding the new DS8000 LUNs to the host and later by removing the old storage. They vary too much from operating system to operating system, even from version to version. However, they have to be taken into account, too.

Once it is decided which method (or methods) to use, the migration process starts with a very careful planning phase. Items to be taken into account during migration planning include:

￿Availability of all the required hardware and software

￿Installation of the new and removal of the old storage

￿Installation of drivers required for the new storage

￿A test of the new environment

￿The storage configuration before, during, and after the migration

￿The time schedule of the whole process, including the scheduling of outages

￿Does everyone involved have the necessary skills to perform their tasks?

Additional information about data migration to the DS8000 can be found in the DS8000 Introduction and Planning Guide, GC35-0495, available for download at:

http://www-1.ibm.com/servers/storage/disk/ds8000/pdf/DS8000_planning_guide.pdf

Exceptional care must be exercised in data sharing (clustered) environments. If data is shared between more than one host, all of them have to be made aware of the changes in the configuration, even if the migration is only performed by one of them. Refer to the documentation of your clustering solution for ways to propagate configuration changes throughout the cluster.

Note: IBM Global Services can assist you in all phases of the migration process with professional skill and methods.

16.2 Comparison of migration methods

There are numerous methods that can be used to migrate data from one storage system to another. We briefly describe the most common ones and list their advantages and disadvantages in the following sections.

Note: The IBM iSeries platform with the OS/400 and i5/OS operating systems has a different approach to data management than the other open systems. Therefore different strategies for data migration apply. Refer to Appendix B, “Using DS8000 with iSeries” on page 373, for more information.

16.2.1 Host operating system-based migration

Data migration using tools that come with the host operating system has these advantages:

￿No additional cost for software or hardware

￿System administrators are used to using the tools

Chapter 16. Data migration in the open systems environment 335