Configuring the delta chain settings
IMPORTANT: The master-delta chain settings should only be adjusted if you are familiar with the data activity patterns of the DS-Clients on your DS-System.
This feature allows the DS-System to be configured with specific master-delta chain reconstruction settings for each backup set type. These changes can be applied at the customer or DS-Client level. This task must be scheduled to run at regular intervals on the DS-System. For more information, see
“Configuring scheduled tasks”.
The global default master-delta chain setting is 9 and applies in the absence of any other configuration. This value is used when the optimization task runs on schedule or on demand to correct the delta chain length for a file's generations. After initial backup, DS-Client normally sends only delta changes to keep the backup times as short as possible. This means the DS-System must regularly run an optimization task on the backup files to rebuild a master when any backup file's delta chain passes its configured limit.
NOTE: Replication DS-Systems only receive deltas, therefore at least one optimization task should be scheduled to periodically fix delta chains.
The ability to customize delta chain configurations is essentially unlimited. You can create new configurations for specific DS-Clients, for specific customers, or for the entire DS-System. The most specific delta chain setting is at DS-Client level and only one setting can apply per DS-Client. This overrides any customer-level configuration, which itself overrides the global default setting for the DS-System.
NOTE: It is important to remember the point of the delta chain length is to set a limit that balances the backup (space) efficiency of the deltas with the restore performance of having a full master and a shorter delta chain.
To configure the delta chain settings:
1. On the Setup menu, click Delta Chain Configuration.
• There is a global default maximum delta chain length. By default, all backup sets will be assigned the global maximum delta chain length (this is the Default delta chain length setting at the bottom of the dialog box).
• Next, the customer level configurations will apply to all the customer’s DS-Clients. All applicable backup sets will have their maximum chain length overridden with customer’s configuration (if applicable).
• Finally, the DS-Client level configurations will override the maximum chain length for backup sets defined in the delta chain configuration.
• You can create and maintain multiple configurations from this dialog box.
• Configurations are applied per DS-Client account. They can be applied at the customer level, but if a customer’s DS-Client is assigned to a different configuration, the DS-Client level assignment will override the customer level assignment.
• Each configuration that is created can be used in any way required by DS-System administrators.
• A configuration can be specific, for a specific backup set type (such as File System). A configuration can be more general, for a group of similar data types like databases (such as Microsoft Exchange Server and Microsoft SQL Server). A configuration can also cover every backup set type and be assigned to one or several customers (or DS-Clients).
2. To add or edit a configuration to the list, click New or Modify in the Configuration section. Type a name for this delta chain configuration setting and click OK. You can create as many configurations as required.
3. Once a configuration is created, you can add details. Each detail will override the DS-System’s default delta chain length for the specified backup set type.
4. To add or edit a configuration’s detail, in the Configuration Details section, click New or Modify. Select the backup set type and assign a delta chain length, and then click OK.
5. Continue with Step 4 until the Configuration contains all the Details required. When you are finished, you can assign this Configuration to customers or DS-Clients.
6. To assign a customer to the configuration, in the Customers assigned to this delta chain configuration section, click Assign.
• In the Assign Customers to delta chain configuration dialog box, select the customer(s) and click Apply.
7. To assign a DS-Client to the configuration, click Assign in the DS-Clients assigned to this delta chain configuration section, click Assign.
• In the Assign DS-Clients to delta chain configuration dialog box, select the DS-Client(s) and click Apply.