Common Hardware Components

All LifeKeeper for Windows configurations share these common components as illustrated in the diagram below:

1. Server Groups. The basis for the fault resilience provided by LifeKeeper for Windows is clustered Windows servers. The servers, also referred to as LifeKeeper for Windows nodes, do not have to be the same hardware platform.

2. Communication paths for heartbeat. The LifeKeeper heartbeat is a periodic message between servers in a LifeKeeper cluster. It is a key fault detection facility. All servers within the cluster require redundant heartbeat communications paths (comm paths) to avoid system panics due to simple communications failures. It is strongly recommended that each pair of servers in the group share at least two communication paths (comm paths), although only one is required. To avoid unnecessary failover due to communication failure, you should configure your redundant comm paths using different protocols and communication media, for example TCP/IP (or socket). LifeKeeper for Windows uses the comm paths to coordinate resource availability for the fault-detection heartbeat, a periodic message between nodes and for switchover of resources. (See Communication Paths.)

*Note: In a cloud environment, the internal configuration of the network is not open to the public, so it is difficult to physically prepare two LAN lines with different routes. Since it is expected that the physical network is basically redundant on the cloud side, operational reliability can be ensured even if there is only one communication path.

3. Shared data resources. LifeKeeper for Windows can recover and restore shared or mirrored data, applications and communication resources. LifeKeeper for Windows controls access at the volume (drive letter) level. In case of a server failure, LifeKeeper for Windows automatically switches availability of protected resources to an active server. Peripheral devices that are to be shared between systems must be packaged in external peripheral cabinets. See the Configuring Your Storage topic for information to help you configure your shared storage.

4. Shared communication for user connections. LifeKeeper for Windows can also automatically manage the switchover of user communication resources, such as IP addresses, computer alias names and file share lists. Switchover of communication resources allows users to connect using their normal paths.