Linux FailSafe supports the following highly available configurations:
Basic two-node configuration
Star configuration of multiple primary and 1 backup node
Ring configuration
You can use the following reset models when configuring a Linux FailSafe system:
Server-to-server. Each server is directly connected to another for reset. May be unidirectional.
Network. Each server can reset any other by sending a signal over the control network to a multiplexer.
The following sections provide descriptions of the different Linux FailSafe configurations.
In a basic two-node configuration, the following arrangements are possible:
All highly available services run on one node. The other node is the backup node. After failover, the services run on the backup node. In this case, the backup node is a hot standby for failover purposes only. The backup node can run other applications that are not highly available services.
Highly available services run concurrently on both nodes. For each service, the other node serves as a backup node. For example, both nodes can be exporting different NFS filesystems. If a failover occurs, one node then exports all of the NFS filesystems.