In DPM, for a file volume or share on a server, the protection agent uses a volume filter and the change journal to determine which files have changed and then performs a checksum procedure for these files to synchronize only the changed blocks. During synchronization, these changes are transferred to the DPM server and then applied to the replica to synchronize the replica with the data source. The following figure illustrates the file synchronization process.
File Synchronization Process
If a replica becomes inconsistent with its data source, DPM generates an alert that specifies which computer and which data sources are affected. To resolve the problem, the administrator repairs the replica by initiating a synchronization with consistency check, also known as simply a consistency check, on the replica. During a consistency check, DPM performs a block-by-block verification and repairs the replica to bring it back into consistency with the data source.
You can schedule a daily consistency check for protection groups or initiate a consistency check manually.
At regular intervals that you can configure, DPM creates a recovery point for the protection group member. A recovery point is a version of the data from which data can be recovered. For files, a recovery point consists of a shadow copy of the replica, which is created by using the Volume Shadow Copy Service (VSS) functionality of the operating system on the DPM server.