Updated: November 1, 2008
Applies To: System Center Data Protection Manager 2007
Synchronization is the process by which DPM transfers data changes from the protected computer to the DPM server and then applies the changes to the replica of the protected data.
For a file volume or share, the protection agent on the protected computer tracks changes to blocks, using the volume filter and the change journal that is part of the operating system to determine whether any protected files were modified. DPM also uses the volume filter and change journal to track the creation of new files and the deletion or renaming of protected files.
For application data, after the replica is created, changes to volume blocks belonging to application files are tracked by the volume filter.
How changes are transferred to the DPM server depends on the application and the type of synchronization. For protected Microsoft Exchange data, synchronization transfers an incremental Volume Shadow Copy Service (VSS) snapshot. For protected Microsoft SQL Server data, synchronization transfers a transaction log backup.
DPM relies on synchronization to update replicas with the protected data. Each synchronization job consumes network resources and can therefore affect network performance.
The impact of synchronization on network performance can be reduced by using network bandwidth usage throttling and compression. For more information, see Using Network Bandwidth Usage Throttling and Using On-the-Wire Compression.