Choosing a Replica Creation Method
Letzte Aktualisierung: April 2010
Betrifft: System Center Data Protection Manager 2010
When you create a protection group, you must choose a method for creating the replicas for the volumes included in the group. Replica creation involves copying all the data selected for protection to the DPM server and then running synchronization with consistency check for each of the replicas.
DPM can create the replicas automatically over the network, or you can create the replicas manually by restoring the data from removable media such as tape. Automatic replica creation is easier, but, depending on the size of the protected data and the speed of the network, manual replica creation can be faster.
To help you choose a replica creation method, the followingtable provides estimates for how long DPM takes to create a replica automatically over the network given different protected data sizes and network speeds. The estimates assume that the network is running at full speed and that other workloads are not competing for bandwidth. Times are shown in hours.
Hours to Complete Automatic Replica Creation at Different Network Speeds
| Size of Protected Data | 512 Kbps | 2 Mbps | 8 Mbps | 32 Mbps | 100 Mbps |
|---|---|---|---|---|---|
1 GB |
6 |
1.5 |
< 1 |
< 1 |
< 1 |
50 GB |
284 |
71 |
18 |
5 |
1.5 |
200 GB |
1137 |
284 |
71 |
18 |
6 |
500 GB |
2844 |
711 |
178 |
45 |
15 |
Wichtig
If you are deploying DPM to protect data over a WAN and your protection group includes more than 5 GB of data, we recommend that you choose the manual method for creating the replicas.
Automatic Replica Creation
For large replica creation jobs, you might want to schedule the job to run only during periods of light network traffic.
Manual Replica Creation
If you choose manual replica creation, DPM specifies the precise locations on the DPM server where you must create the replicas. Typically, you create the replicas by restoring your most recent backup of the data source from removable media such as tape. After you restore the data, you complete the process by running synchronization with consistency check for each of the replicas.
It is crucial that when you restore the data to the DPM server to create the replica, you retain the original directory structure and properties of the data source, such as time stamps and security permissions. The more discrepancies that exist between the replicas and the protected data source, the longer the consistency checking part of the process takes. If you do not preserve the original directory structure and properties, manual replica creation can take as long as automatic replica creation.