16.20 - Restoring Data to a Smaller System - Teradata Vantage NewSQL Engine

Teradata Vantageā„¢ NewSQL Engine Node Software Migration Guide

Teradata Database
Teradata Vantage NewSQL Engine
March 2019

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 is smaller than the source system, contact Teradata Customer Services for site-specific instructions to ensure a successful migration.

If the source system has more physical data than can fit on the target system, you must exclude some databases from the restore operation until the amount of data being restored is less than the physical disk space available on the target system.

It is more common to run out of logical space (rather than physical space) on the target system. This is the case when the physical disk space on the target system (max perm) is actually sufficient to hold all of the existing data from the source system (current perm), but the amount of max perm physical disk space on the source system is larger than the physical disk space on the target system. This situation causes the current perm space for database DBC on the target system to become negative. When that happens, any SQL statement that requires any additional space fails, and reports an out of space error.If you encounter this situation, you can contact Teradata Support to temporarily have these errors ignored during the migration.