Configuring the delta chain settings
You can configure the DS-System with specific master-delta chain reconstruction settings for each backup type. These changes can be applied at the customer or DS-Client level and the task can be scheduled to run at regular intervals on the DS-System. For more information, see
“Configuring scheduled tasks”.
IMPORTANT: The delta chain length sets 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. You should adjust the master-delta chain settings only if you are familiar with the data activity patterns of the DS-Clients on your DS-System.
The global default master-delta chain setting is 9 and is applied 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 the initial backup, the DS-Client normally sends only delta changes to keep the backup times as short as possible. The DS-System must regularly run an optimization task on the backup files to rebuild a master when the delta chain of a backup file crosses the configured limit.
NOTE: Since replication DS-Systems only receive deltas, at least one optimization task must be scheduled to periodically fix delta chains.
You can configure delta chain settings for specific DS-Clients, customers, or the entire DS-System. The most specific delta chain setting is at the 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.
To configure the delta chain settings:
1. On the Setup menu, click Delta Chain Configuration.
2. Under Configuration, do one of the following:
• To add a delta chain configuration, click New. Type a name for the delta chain configuration, and then click OK.
• To modify a delta chain configuration, select the configuration, and then click Modify. Type a name for the delta chain configuration, and then click OK.
• To update the list, click Refresh.
NOTE: To delete a delta chain configuration, select the configuration, and then click Delete.
3. Under Configuration Details, do one of the following:
• To add a delta chain configuration detail, click New. Select the backup type, enter the delta chain length, and then click OK.
• To modify a delta chain configuration, select the configuration, and then click Modify. Select the backup type, enter the delta chain length, and then click OK.
• To update the list, click Refresh.
NOTE: To delete a delta chain configuration, select the configuration, and then click Delete.
4. Under Customers assigned to this delta chain configuration, do the following:
a) To assign a customer to a delta chain configuration, click Assign.
b) In the Assign Customers to delta chain configuration dialog box, select the customer(s) you want to assign to the delta chain configuration, and then click Apply.
c) When finished, click Close.
NOTE: To delete a customer from a delta chain configuration, select the customer, and then click Remove.
5. Under DS-Clients assigned to this delta chain configuration, do the following:
a) To assign a DS-Client to a delta chain configuration, click Assign.
b) In the Assign DS-Clients to delta chain configuration dialog box, select the DS-Client(s) you want to assign to the delta chain configuration, and then click Apply.
c) When finished, click Close.
NOTE: To delete a DS-Client from a delta chain configuration, select the DS-Client, and then click Remove.
After you have created at least one delta chain configuration, you can schedule the DS-System to run the optimization task. For more information, see
“Scheduling delta chain optimization”.