Migration plans

Before you begin to migrate to a new version of the database server, you should plan for migration.

To plan your migration requirements, complete these tasks:

  1. Inventory the existing Informix® environment assets, such as machines, instances, databases, database customization, custom code, IBM® software, and third-party software.
  2. Itemize the requirements for the post-migrated environment. New requirements can include upgrading or adding hardware, using new features, or replacing custom-code with new built-in function.
  3. Plan the migration activities. Typical activities include:
    • Performing a level-0 backup of the database.
    • Quiescing the database server and preventing connections to the database until migration completes.

      Important: Any connection attempts (for example, from cron jobs or monitoring scripts) to the database after you quiesce the database server and during migration will cause migration to fail.

    • Installing the new version of Informix.
    • Migrating database data.
    • Reverting to the previous version.
    • Migrating applications before using them with the new database server.

Depending on your environment, you might need to perform some of these activities more than once. You might not need to restore the level-0 backup; however, if you encounter problems you can always restore the backup of your current server.