Bringing a Service Group Online

The time it takes to bring a service group online depends on the number of resources in the service group, the service group dependency structure, and the time to bring the group's resources online. For example, if service group G1 has three resources, R1, R2, and R3 (where R1 depends on R2 and R2 depends on R3), VCS first onlines R3. When R3 is online, VCS onlines R2. When R2 is online, VCS onlines R1. The time it takes to online G1 equals the time it takes to bring all resources online. However, if R1 depends on both R2 and R3, but there was no dependency between them, the online operation of R2 and R3 is started in parallel. When both are online, R1 is brought online. The time it takes to online the group is Max (the time to online R2 and R3), plus the time to online R1. Typically, broader service group trees allow more parallel operations and can be brought online faster. More complex service group trees do not allow much parallelism and serializes the group online operation.