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Things to Consider when Creating and Configuring DB2 Subclients
The following table shows subclient creation and configuration details specific to the DB2 iDataAgent.
Agent |
Type of Data | Default Subclient created during install of the Agent | Supports Default Subclient | Supports User Defined Subclient | Contents of the default subclient when user-defined subclient is present | Other Types of subclients supported by the Agent | Notes |
| DB2 iDataAgent | database, subset(s), table space(s), log file(s) |
No | Yes | Yes | all database objects not assigned to other subclients, unless otherwise configured* | None |
|
Before you back up data, you must define the data that you want to back up and how this data should be backed up. This is done by creating one or more subclients for the database(s) that you are backing up. For the DB2 iDataAgent, a subclient defines whether:
Depending on your needs, you can create multiple subclients for backing up an entire database, individual table spaces, multiple table spaces, and log files with the database either online or offline.
The DB2 iDataAgent is designed to back up and restore DB2 databases, which include DB2 database files along with the associated table spaces, history files and log files. After you install a DB2 iDataAgent, a default subclient is created by the system only after you first create and configure a DB2 instance and then an associated backup set from the CommCell Console. Since each DB2 backup set is designed to represent a single DB2 database, the default subclient that is created for a backup set will include the entire DB2 database for that backup set. However, you can use the CommCell Console to create user-defined subclients to distribute some of the database content by configuring the Subclient Properties (Content) tab. Any content that you do not distribute to the user-defined subclients will remain in the default subclient. Since multiple DB2 databases can be backed up from the client, you can create multiple backup sets on the client and therefore multiple user-defined subclients for these backup sets.
When you configure subclient content, you click the Subclient Properties (Content) tab for the subclient to view the eligible data for inclusion in the subclient content. You then select an option to include either the entire database or one or more table spaces in the database within the subclient content. If you opt to include just one or more table spaces, you then click the desired table spaces to configure the content for the subclient. Once you do this, the subclient content may be displayed as follows:
In this example, PUBS is the name of the database (and the backup set), and two of the three table spaces in the database (TEMPSPACE1 and USERSPACE1) have been included in the subclient content.
To include log files in the subclient content, you should ensure that the appropriate option in the Subclient Properties (Backup Arguments) tab is selected (this is done by default). However, it is recommended that you configure separate user-defined subclients for log file content.
A useful way to distribute subclient content for this iDataAgent is to create separate user-defined sublients for frequently used table spaces and also for log files. For example, if the SYSCATSPACE and USERSPACE1 table spaces shown above undergo frequent changes, you can create a separate subclient for each table space. For example:
Content:
SYSCATSPACE
Content:
USERSPACE1
It is recommended that you create a separate user-defined subclient for the DB2 log files on the client. For example:
Content:
(all the DB2 log files)
Distributing the client data using subclients in this way can help improve backup performance by distributing the workload on the client into logical groupings.
Data protection filtering is not applicable for this agent.
Wildcards and regular expressions are not supported for this agent when defining subclient content.
For more information, see Things to Consider when Creating and Configuring DB2 Subclients.
Once installed, the agent is configured and is therefore able to manage the data or volumes on the client computer. However, you can change certain aspects of the subclient configuration to manage the data in the manner that best suits your needs.
You can view or change the subclient configuration from the Subclient Properties dialog box. The following information can be configured.
You can enable or disable all operations for this CommCell object and all objects below it. For more information, see Activity Control.
Some database iDataAgents run backups using a system-generated script that is run behind the scenes from a command line. The CommCell Console serves as a front-end user interface for specifying 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.
You can set the number of backup streams. For more information, see Streams.
You can define the content of the subclient. Most agents include a configure button that displays a dialog where you can add or modify the data included as subclient content. For step-by-step instructions, see Configure Subclient Content.
Several configurable options to efficiently use available resources for transferring data secured by data protection operations are provided in the subclient. This includes the following:
You can enable or disable the encryption of data for transmission over unsecure networks and for storage on media. For more information, see Data Encryption.
You can view the data paths associated with the primary storage policy copy of the selected storage policy or incremental storage policy. You can also modify the data paths for the subclient including their priority. For additional information, see Configuring Alternate Data Paths for Subclients.
You can add, modify or view Pre/Post processes for the subclient. These are batch files or shell scripts that you can run before or after certain job phases. For more information, see Pre/Post Processes.
You can associate the subclient to a storage policy. For more information, see Storage Policies.
You can rename a user-defined subclient.
The following pertains to DB2 on Windows:
You can define an account with permissions to execute Pre/Post commands for the agent's archive, backup, or volume creation jobs.
See DB2 iDataAgent: Other User Accounts in User Accounts and Passwords for more information.
When creating and configuring subclients for DB2 agents, keep in mind the following considerations:
We recommend that you do not re-configure the content of a default subclient because this would disable its capability to serve as "catch-all" entity for client data. As a result, the likelihood that some data will not get backed up or scanned for archiving would increase.