Most full-system migrations involve destination systems with sufficient space for the operation. In rare exceptions, or when a disaster-recovery system is not the same configuration as the production system, the destination system may be smaller than the source system. In such cases, restoration may fail due to insufficient space.
If the destination system has insufficient space for a database, the restoration of that database fails. Additional space must be given to the database on the destination system before the database can be restored successfully. In addition, other databases included in the same restoration job that were successfully restored prior to running out of space must be restored again in order to migrate the statistics, join indexes and hash indexes. Statistics, join indexes, and hash indexes are processed during the build phase of the restoration process, and the information is kept in memory. If the restoration job fails to complete, that information is lost unless the entire restoration job is restarted. For this reason, breaking user data into multiple smaller archives in preparation for migration is recommended over creating a single archive containing all databases.
If the destination system is smaller than the source system, contact Teradata Customer Services for site-specific instructions specific to ensure a successful migration.