15.00 - Reconfiguration Considerations - Teradata Database

Teradata Database Support Utilities

Teradata Database

Reconfiguration Considerations

MOVE AMP Operation

In a MOVE AMP operation, Reconfiguration copies all rows from the Move-From AMP to the Move-To AMP.

Note: MOVE AMP is available only during offline reconfigurations.

You can move a range of AMPs to another range of AMPs; however, a one-to-one correspondence between the Move-From AMPs and the Move-To AMPs must exist.

The following sequence discusses the state of these AMPs before, during, and after the reconfiguration process.

1 The Parallel Upgrade Tool (PUT) is used to start the reconfiguration process. During this step, PUT identifies new AMPs on the system. Some of these new AMPs may have been added, and some may be targets of the MOVE AMP process. PUT must be used at this time to identify which AMPs are the move-to AMPs and which are the move-from AMPs.

2 The Configuration utility (config) is used to complete the DBS configuration of AMPs in regards to adding and moving AMPs, and defining the cluster configuration. The move-to AMPs and the move-from AMPs specified in the config commands must match the MOVE AMP definitions specified during the PUT process

3 Prior to and during most of the reconfiguration process, the Move-To AMPs are configured as new AMPs, just as if you added them. Move-To AMPs have their own vproc numbers and associated storage. PUT sets up the relationship between an AMP and its storage.

4 The file system tracks which storage belongs to which AMPs by inserting the AMP number in the cylinder indexes written with each cylinder. This allows the file system to verify that multiple AMPs do not write to the same cylinder of storage.

5 When almost finished, Reconfiguration saves the Teradata Database configuration maps to indicate the new configuration.

6 Reconfiguration notifies the file system to update the cylinder indexes to indicate the change in storage ownership.

7 Reconfiguration sets a control flag to keep Teradata Database in a DOWN state and to initiate a restart.

8 While Teradata Database is in a DOWN state, PUT exchanges the storage mapping between the Move-From and Move-To AMPs.

For additional information on the MOVE AMP command, see “Configuration Utility” in Support Utilities.