How to select a data migration method

The data migration method that you select must provide the best compromise between efficiency and impact on the system users. The selected method can provide a simple but robust method that minimizes user impact.

Most methods of data migration affect the everyday operation of a computer system. When data is moved, the data must be in a certain state, and typically requires that updates or changes cease while the movement occurs. Depending on the amount of data that you are moving and your migration method, data can become unavailable for up to several hours. The following factors might contribute to the migration time:
  • Creating new logical volumes or file systems
  • Modifying configuration files
  • Receiving integrity checks
You can consider the following items to determine the best method for your data migration:
  • Management software provides simple robust methods that you can use during production without disturbing users.
  • The AIX® logical volume manager (LVM) provides methods that you can use at any time without disrupting user access to the data. You might notice a small performance degradation, but this method is preferable to shutting down databases or requiring users to log off the system.
    • AIX and HP-UX 11.xx are included with logical volume management (LVM) software as part of the base operating system. LVM provides complete control over all disks and file systems that exist on an AIX system. HP-UX has similar volume management software.
    • Oracle has a basic volume management product that is called Solstice, which is available for the Solaris systems.
    • Linux® systems also use the LVM.
  • Methods that use backup and restore procedures have the most impact on the system usage. They require that databases and file systems be in quiescent states to ensure a valid snapshot of the data.