Subclients - Informix

Things to Consider when Creating and Configuring Informix Subclients

Overview

The following table shows subclient creation and configuration details specific to the Informix agent.

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
Informix iDataAgent	database, subsets, log files	No	Yes	Yes	database objects not assigned to other subclients, unless otherwise configured*	None	After installing the agent, manually create the instance, then the default subclient will be automatically generated. *See Caution Against Re-configuring Default Subclient Content.

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 that you are backing up. For the Informix iDataAgent, a subclient defines:

Whether the entire database will be backed up as a whole or only as a subset of objects within the database
Whether the data intended for backup will be backed up serially or in parallel
Whether the logical log files should be included in the database backup

Depending on your needs, you can create multiple subclients for one or all of the following:

Entire database(s)
Database subsets
Whole system backups in parallel
Whole system backups in serial
Selective backups in parallel
Full logical logs backups
Full and current logical logs backups

Subclient Content

The Informix iDataAgent is designed to back up and restore Informix databases, which include Informix database files along with the associated logical log files, emergency boot files (ixbar), and ONCONFIG files. After you install an Informix iDataAgent, a default subclient is created by the system only after you first configure an Informix instance from the CommCell Console. Since each Informix instance is designed to include one or more Informix databases, the default subclient that is created for an instance will include all the Informix databases for that instance. 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.

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 one of the following in the subclient content: entire database, one or more dbspaces (subsets) in the database, logical logs that are filled up as well as the logical logs to which the system is still writing, or only logical logs that are filled up. If you opt to include the entire database in the subclient content, you can select an option to set up the data to be backed up either in parallel mode or serial mode.

If you opt to include just one or more dbspaces (subsets) in the subclient content, you click the appropriate option and then the desired dbspaces to configure the content for the subclient. Once you do this, the subclient content may be displayed as follows:

In this example, inf_10 is the name of the instance, and this instance includes a single database. The database includes five dbspaces, and two of the five table spaces in the database (testdbs1 and testdbs2) have been included in the subclient content.

Also, it is recommended that you create a separate user-defined subclient for Informix log files, and you can select options to include the Emergency Boot File (ixbar) and the ONCONFIG file in the subclient client.

A useful way to distribute subclient content for this iDataAgent is to create separate user-defined sublients for frequently used dbpaces and also for log files. For example, if the testdbs1 and testdbs2 dbspaces shown above undergo frequent changes, you can create a separate subclient for each dspace. For example:

User-defined subclient: Test1
Content:

testdbs1
User-defined subclient: Test2
Content:

testdbs2

It is recommended that you create a separate user-defined subclient for the Informix log files on the client. For example:

User-defined subclient: Logs
Content:

(all the Informix 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.

Filtering

Data protection filtering is not applicable for this agent.

Wildcards and Regular Expressions

Wildcards and regular expressions are not supported for this agent when defining subclient content.

Considerations

For more information, see Things to Consider when Creating and Configuring Informix Subclients.

Configurable Properties

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.

Activity Control

You can enable or disable all operations for this CommCell object and all objects below it. For more information, see Activity Control.

Backup Arguments

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.

Backup Streams

You can set the number of backup streams. For more information, see Streams.

Content/Databases

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.

Data Transfer Options

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:

Enable or disable Data Compression either on the client or the MediaAgent.
Configure the transfer of data in the network using the options for Network Bandwidth Throttling and Network Agents.

Data Encryption

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.

Data Paths

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.

Pre/Post Processes

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.

Storage Policies

You can associate the subclient to a storage policy. For more information, see Storage Policies.

Subclient Name

You can rename a user-defined subclient.

Configuring User Defined Subclients

You can create user-defined subclients to perform backup and restore operations under specific circumstances. For example, if you use the CommCell Console to back up and restore Informix database objects (subsets/dbspaces), then you will need to create a subclient.

Creating a Subclient to Backup Logical Logs

You can recover database transactions that have been lost due to an operating system or disk failure by applying the backed up logical logs to an online backup. Informix archives logical log files once they become full. Due to their importance in recovering the data, you must create separate subclients to backup the log files.

From the CommCell Browser, navigate to <Client> | iDataAgent.
Right click the <Instance>, point to All Tasks and then click New Subclient.
In the Subclient Name box, type a name.
Click the Content tab.
Click Full and Current Logical Logs or Full Logical Logs Only as backup mode.
Click the Storage Device tab.
In the Storage Policy list, click a storage policy name.
Click the Activity Control tab.
Select Enable Backup check box, if it is not already selected from the Agent level.
Click OK.

Things to Consider when Creating and Configuring Informix Subclients

When creating and configuring subclients for Informix agents, keep in mind the following considerations:

Informix subclients include one or more dbspaces. As databases are added to the dbspaces, the subclients are updated automatically. This process is referred to as an Automatic Subclient Update.
Informix has configuration requirements to define the backup mode, backup level and decide whether to back up the emergency boot file and/or the ONCONFIG file, in addition to specifying the subclient name, content and storage policy association.
If you will be using the Informix ONBAR utility to back up and restore data, you need not create subclients.
Logical logs are used to recover database transactions that have been lost due to an operating system or disk failure. This recovery is done by applying the logs to an online backup. Informix archives logical log files once they become full. Because of their importance in recovering data, it is suggested that you create separate subclients for backing up logical log files.
It is recommended that you include the control files with the appropriate database backups.
Caution Against Re-configuring Default Subclient Content
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.