Migrate from Exasol 7.1 to Exasol 8

This section explains how to migrate an existing Exasol 7.1 database to Exasol 8.

Because of the differences in architecture, you cannot update your database directly from Exasol 7.1 to Exasol 8. In order to migrate your database to Exasol 8 you must create a full backup (level 0 + level 1) of your Exasol 7.1 database and then restore that backup into a new Exasol 8 database.

Downtime

The total downtime required to complete the migration procedure mainly depends on the duration of the backup and restore operations. A restore normally takes the same amount of time as the backup. For example: a level 0 backup takes approximately 5 hours, and the level 1 backup takes 30 minutes. The total downtime will then be at least 6 hours (creating level 1 + restoring level 0 + restoring level 1).

When you calculate the total downtime for the migration, allow time for additional operations such as starting and stopping databases, and for reverting to the previous version in case the migration fails. Also consider network speed and other factors in your system environment that might affect the operation.

To minimize downtime, we recommend that you prepare the new (empty) Exasol 8 database before you start on the backup procedures in the existing Exasol 7.1 database.

To prevent risk of data loss or excessive downtime during the update, read Update Considerations carefully before you start the migration procedure.

Prerequisites

  • An Exasol database running on the latest Exasol 7.1 version.

  • A valid Exasol 8 license.

    Exasol 7.1 licenses are not valid in Exasol 8 because of differences in the license format. For more information about how to obtain a valid license for Exasol 8, contact support.

Procedure

The migration procedure consists of a number of actions to be carried out in Exasol 8 as well as in Exasol 7.1. The following is an overview of the required steps in the procedure. For more details about the actions required to complete each step, click on the link in the step.

  1. Create a new Exasol 8 deployment with the same number of nodes as the Exasol 7.1 database.

    The Exasol 8 database must have the exact same number of nodes as the database that was backed up. Otherwise, the migration will fail.

  2. Create a level 0 backup of the Exasol 7.1 database.

    • The backup must be stored in a remote archive volume that is reachable by both the Exasol 7.1 database and the Exasol 8 database. If necessary, create a new remote archive volume before taking a backup.
    • The level 0 backup can run without any downtime.
  3. Create a remote archive volume in the Exasol 8 database that points to the source that contains the backup of the Exasol 7.1 database.

  4. Stop the Exasol 7.1 database.

    The downtime for the migration procedure begins at this point.

  5. Change the connection port of the Exasol 7.1 database. This ensures that clients are not able to connect to the database during the migration procedure.

  6. Start the Exasol 7.1 database.

  7. Create a level 1 backup of the Exasol 7.1 database.

  8. Stop the Exasol 7.1 database.

  9. Restore the Exasol 8 database from the level 1 backup of the Exasol 7.1 database.

    • Restoring the level 1 backup also restores the level 0 backup. All data from the moment that the level 1 backup started is restored.
    • The Exasol 8 database will be automatically restarted when the restore operation has completed.
    • The downtime for migration ends at this point.

The migration is now complete and your Exasol 8 database should be running. Make sure to inform all users about any changes in how to connect to the database, such as modifying the connect string.

Fallback

If the migration is not successful, you can restart the Exasol 7.1 database on the default port and continue working in that version.

Support

To get help, create a case.