… Migrate an instance

The procedure of instance migration is similar for all instance types, although some types have their own particularities. The procedure itself may vary, depending on whether this is a scheduled operation or an urgent recovery after a server failure.

In this chapter we will show you how to migrate an instance from one physical server to another as part of a scheduled operation. We will assume that on a new server you will use a new IP address for the migrated instance.

1. (Optional) Go to the Servers page and create a new server.
2. On a target (new) server add a dedicated IP address to be used for the migrated instance.
3. Create a new configuration (referred to as Configuration A later on) as a clone of the currently active configuration:
   • Clone the currently active configuration.
   • Delete old instances that are to be migrated from the former server.
   • Save and close this new configuration but do not yet apply it.
4. Create another new configuration (referred to as Configuration B later on) as a clone of the currently active configuration:
   • Clone the currently active configuration.
   • Modify instances that are to be migrated to the target server:
     • Select the instance and click Update Instance.
     • Select a new server on which this instance will run.
     • Specify a new Service IP.
     • Press OK.
   • Save and close this new configuration but do not yet apply it.
5. Check and apply both new configurations one by one (note that service downtime is required to apply changes):
   • Open Configuration A and click the Verify button to make sure that it contains all the required changes and that no unwanted options were modified by mistake. Then, click the Check/Apply button to verify if the configuration is valid.
   • When the check is done click the Apply button.
   • Close Configuration A.
   • Open Configuration B and click the Verify button to make sure that it contains all the required changes and that no unwanted options were modified by mistake. Then, click the Check/Apply button to check if the configuration is valid.
   • When the check is done click the Apply button.

The Configuration server will apply the new configurations by performing the following steps:

1. Configuration A:
   • New IP addresses will be added to the target server.
   • Instances will be removed from the former server.
2. Configuration B:
   • Instances will be created and started on a target server.

Make sure to consider the following tips:

• Some instance types cannot run from one server (see the Add Instances section for more details).
• If the log server is configured, it will continue writing log files for the migrated instance, otherwise new log files will be created on the target server.
• If you have a web cluster then you can migrate web instances one by one without initiating a service outage, otherwise use the migration plan above for web instance migration.
• To migrate a DB instance (either Master DB or Replica DB) you need to manually copy the database (e.g.,  using a snapshot) to a target server and then update the instance using the migration plan.

Note that you may want to set up replication from the currently active database to the new one (e.g., configure the currently active Master DB > New Master DB > Replica DB replication when the copy process is finished) to keep the services running while the database is being copied. This decreases the services outage time during the migration. If you do this, then do not forget to stop the services and the replication just before applying the new configurations.