Determining sizing requirements for Oracle databases
Before running BMC BladeLogic Data Migration Manager, you must ensure that your Oracle database has the free space required for successful data migration to version 8.3. To determine those requirements, use the sizing_8x_temp_undo.sql script provided by BMC Server Automation.
The script provides minimum space requirements for these migration paths:
- Migration from version 8.2.x to version 8.3.00
- Migration from version 8.1.x to version 8.2.00
- Migration from version 8.0.x to version 8.1.00
- Migration from version 7.6.x or 7.7.x to 8.0, when executed as part of a chained migration to 8.1.0.
The script provides space requirements for these Oracle space characteristics:
- UNDO tablespace size
- TEMP tablespace size
- Extra free space in the tablespace holding the table data
- Extra free space in the tablespace holding the index data
Before you begin
Locate the sizing_8x_temp_undo.sql script. If you extract the entire contents of external-files.zip, the script is located in the /db_scripts/oracle/utility/migration_sizing_8x_temp_undo directory.
To determine minimum size requirements for Oracle data migration
Use the following command to execute the sizing script:
sqlplus <blcore_db_username>/<password>@<connectIdentifier> @sizing_8x_temp_undo.sql
- <blcore_db_username> is the database user name
<connectIdentifier> is a TNS alias, a fully qualified TNS connection descriptor, an EZ-Connect string, or an instance System Identifier (SID)
The script creates an output file (sizing_ora_mig_to_830_output.txt) in the directory in which you executed the command.
The output includes these sections:
- Migration Path 8.1.x to 8.2.0
- Migration Path 8.0.x to 8.1.x
- Migration Path 7.6.x or 7.7.x to 8.0
- Use the output to compare the value for each resource of a migration path (TEMP, UNDO, data free space, and index free space) to its corresponding value in the other paths of your data migration. Select the largest value as the minimum space requirement for each resource.
BMC recommends a minimum size requirement of no less than 4 GB for each resource.
For example, suppose you are migrating data from version 7.6.x or 7.7.x to version 8.2.0. If TEMP SPACE REQUIREMENTS has the following values:
- Migration Path 8.1.x to 8.2.0: 7.9 GB
- Migration Path 8.0.x to 8.1.x: 72.22 GB
- Migration Path 7.6.x or 7.7.x to 8.0: 300.69 GB
You would use 300.69 GB as the minimum requirement for TEMP SPACE.
It is assumed that no other load is placed on the database instance during the migration process; that is, application services are down and no other applications are competing for shared server resources.
If your environment is shared with other applications, after you determine the TEMP and UNDO disk space requirements for migrating your BMC Server Automation data, add those to the cumulative minimum requirements for TEMP and UNDO disk space for your other applications. Before executing the data upgrade, make sure that the total TEMP disk space requirements and total UNDO disk space requirements for BMC BladeLogic Data Migration Manager and all other applications are available.
The following table shows an example:
TEMP Disk Space Requirement
UNDO Disk Space Requirement
BMC Server Automation
These guidelines assume that you do not use archive logging while the BMC BladeLogic Data Migration Manager is executing. If for some reason you cannot turn off archive logging in your environment, you need to allocate additional archive log space for the duration of the data upgrade.