When you create a new protection group, Data Protection Manager (DPM) allocates disk space for the protection group in the storage pool. Based on the size of the protected volume, DPM recommends the amount of disk space to allocate in the storage pool and verifies that the protected computer contains sufficient space for the change journal.
If you are protecting only a subset of the data on the protected volume, you can calculate the size of the protected data so that DPM can adjust its recommendations for disk allocation. To compute the disk allocation using the size of the data on the protected volume, in the Modify Disk Allocation dialog box, click Calculate.
If the data on the protected volume outgrows the initial allocations, DPM generates a “Recovery point volume threshold exceeded” alert and provides guidance for increasing disk allocations appropriately.
During creation of a protection group, DPM calculates default space allocations depending on what type of datasource is being protected. You should accept the recommended disk allocations for the protection group unless you are sure that these allocations do not meet your requirements. If you change the recommended allocations, you might get fewer recovery points than you wanted or DPM might allocate more disk space than is needed.
Generally, the recommended allocations provide sufficient storage for at least a couple of weeks of recovery points. If necessary, you can adjust the disk allocations after monitoring disk usage for data protection.
For more information about disk allocations, see Planning Protection Groups in the DPM 2007 Planning Guide (http://go.microsoft.com/fwlink/LinkId=91849).
You can schedule and view reports in the Reporting task area. To view trends in disk usage for a protection group, review a Disk Utilization Report.