As part of an overall High Availability solution, Serviceguard ensures that our critical applications are running for the maximum amount of time. We have discussed many of the tasks involved in managing a cluster and its associated applications and should not lose site of the fact that the underlying principles of what constitutes a failure are still valid. We need to remember that Serviceguard is only part of the solution. While Serviceguard is good at monitoring many of the critical resources associated with an application, Serviceguard cannot fix the problems it finds. Throughout this book, we have stressed the need to maintain High Availability practices throughout our configuration tasks. Think back to our discussions regarding peripherals in Chapter 4, "Advanced Peripherals Configuration," where we discussed OLA/R, the process of adding and replacing interface cards while the system is still running. All of these tasks go toward an entire ethos of high availability. We need to ensure that we monitor all of our system resources carefully and continuously. A failed disk drive can introduce a Single Point Of Failure into an otherwise highly available solution. If and when we detect these problems ”be it a disk drive, the Quorum server, or a LAN card ”we need to be in a position to effect a change in the shortest time possible with as little interruption as possible.
In the next section, we look at a tool that allows us to monitor and manager Serviceguard clusters via a GUI interface.
