Backup - DB2

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Overview

Supported Backup Types

DB2 Backup Jobs

Backup Considerations

Advanced Backup Options

Overview

Plan your backup jobs for this agent by reviewing the following information:

• For an overview of backup jobs, see Backup Data.
• For a list of supported data types for this agent, see Supported Data Types.
• For information on subclients, see Subclients
  • For information on configuring subclients for this agent, see Subclients - DB2.

Supported Backup Types

This agent supports the following backup types:

• Full Backups
• Delta Backups
• Incremental Backups

DB2 Backup Jobs

This agent has the following unique functionality.

Delta Backups

For the DB2 iDataAgent, Delta backup works as described in Incremental Backups. See Incremental Backups for information on DB2 Delta backups.

Backup Arguments

Some database iDataAgents conduct backups through the use of a system-generated script that is run behind the scenes from a command line. The CommCell Console serves as a front-end user interface that allows you to specify various backup arguments and parameters that are passed to the backup script that is run. Depending on your agent you can specify for example, the application-specific Backup Level, whether the backups will be online or offline, as well as buffer and bundle sizes among other settings. Although the backup arguments/parameters vary among iDataAgents, they all function in a similar manner. These arguments are set at the subclient level from the respective iDataAgent's subclient properties dialog box tab.

For step-by-step instructions, see Configure Backup Arguments.

Enable Database Configuration Parameters for DB2 Backups

Each DB2 database has its own configuration. To back up DB2 data successfully in some cases, you must enable the appropriate database configuration parameter(s). You must set these parameters based on the state of the database, backup type, and/or data type as follows:

• Online Backups - To back up any type of DB2 data online, enable the LOGRETAIN or USEREXIT database configuration parameter by entering either of the following commands:
  
  Db2 update database configuration for <database name> using LOGRETAIN on
  
  Db2 update database configuration for <database name> using USEREXIT on
   
• Delta/Incremental Backups - To run delta or incremental DB2 backups, enable the TRACKMOD database configuration parameter by entering the following command:
  
  Db2 update database configuration for <database name> using TRACKMOD on

  Whenever you change the TRACKMOD database configuration parameter, be sure to run a full offline database backup. Otherwise, the TRACKMOD parameter will not take effect.

• Log Backups - To back up DB2 log files, enable the USEREXIT database configuration parameter by entering the following command:
  
  Db2 update database configuration for <database name> using USEREXIT on
  
  The USEREXIT program takes the logs from the DB2 directory and transfers them first to the threshold directory that was defined during the DB2 iDataAgent install and then to tape. If you subsequently use the Delete option, the logs are deleted from the threshold directory; otherwise, the logs are kept in this directory. By default, the threshold directory can hold 1000 logs. If the threshold directory attempts to hold more than 1000 logs, a command line backup for the logs starts automatically, and the logs are transferred to tape.

Backup Considerations

Before performing any backup procedures for this agent, review the following information:

• If you perform a backup of the default subclient without changing its default properties, the backup would include all the objects in the database, including any new objects that may have been created.

  If you have created subclients for databases, and if you have included the log files in these subclients, you can create a complete backup of the database by backing up these subclients. If you have created a group of online subset subclients for the database, you must back up all of these subclients to create a complete backup. If you have created separate subclients for log files, and if they are not included with the subclients defined for databases or subsets, then the subclients for log files must also be backed up to create a complete backup.

• Multiple streams are supported for data protection and recovery operations with this agent; however, before utilizing multiple streams, you should understand how their use affects operations. For more information, see Streams.