Managing an N1 configuration
An N+1 DS-System configuration consists of at least three DS-System nodes on the same LAN working together to provide backup and restore services for DS-Clients. Each DS-System node performs its own storage and retrieval activities, but shares a common database and online storage.
NOTE: The DS-System must be licensed for this type of configuration in the DS-License Server. For more information, see the DS-License Server User Guide.
To ensure the nodes do not run conflicting activities, one node is chosen as the DS-Director. The DS-Director node keeps track of the data storage, sends notifications, and distributes scheduled activities for the entire N+1 DS-System.
NOTE: For an N+1 DS-System with 10 or more nodes, the DS-Director is dedicated to DS-Director tasks only.
All the nodes share the backup processing load. If a node fails, the N+1 DS-System continues running as long as more than half of its nodes are active. This is represented by the formula (n/2)+1, as shown in Table 14.
Table 1 N+1 DS-System configuration formula
Total number of nodes | Minimum number of active nodes required to keep system running | Maximum number of inactive nodes |
|---|
3 | 2 | 1 |
5 | 3 | 2 |
8 | 5 | 3 |
If the number of active nodes is less than the minimum number required to keep the system running, the N+1 DS-System switches to standby mode and waits until enough DS-System nodes start before accepting connections.
NOTE: For detailed instructions on how to install and configure an N+1 DS-System, see the Server Software Installation Guide.
