Working with backup sets : About backup sets : Backup considerations : Enabling Continuous Data Protection (CDP)
 
Enabling Continuous Data Protection (CDP)
When CDP has been enabled in a backup set, the backup trigger is the detection of a change to a file on the backup source. CDP is available in these backup set kinds:
• File system backup sets (Windows / UNIX DS-Client)
NOTE:  CDP supports pure file system backup items only. System Status and Services Database are not supported.
• Email message backup sets of Microsoft Exchange Server using EWS (Windows DS-Client)
Prerequisites for continuous data protection:
Before using CDP in backup sets, you must do the following:
• Know your data environment. Statistical backups and LAN Storage Discovery can help you to assess your data environment. See “Statistical backup sets” and “About the LAN Storage Discovery Tool”.
• Consider the number of generations that you want to maintain online. Normally, each change counts as a generation. The file change detection method depends on the operating system and backup set kind. Backup frequency depends on the interval for changes selected, which can be wide (up to many hours) or precise (down to the second-level).
• Ensure the system clocks on the DS-Client computer and the backup source computer are synchronized. CDP is a time-sensitive operation.
• For CDP in Microsoft Exchange Server backup sets that use EWS, also ensure the following:
– That Autodiscover has been enabled on the Exchange server.
– That the address that Autodiscover provides is resolvable.
– That the internal network in which data requires CDP backups has a DNS server / hosts file configuration.
– This ensures that, when the client attempts to connect to the Exchange server via the FQDN provided by the Autodiscover service, an IP address of the Exchange server can be returned. This is because the name provided by the Autodiscover service is not an IP address but a FQDN or a domain name, for example, ewsserver.example.com.
You can enable CDP when creating a new backup set or after a backup set has been created.
To enable continuous data protection, do one of the following:
• In the New Backup Set Wizard, on the Specify backup set options page, select Continuous data protection, and then click [>>].
• In the Options tab of a backup set’s properties, select Continuous data protection, and then click [>>].
For more information about CDP, see the Knowledge Base article in “Continuous data protection (Backup set option)”.