In this example, a
While this configuration is supported, it is not recommended because the blade enclosure is considered a single point of failure (SPOF) that could potentially fail and bring down the entire cluster. However; one recommended best practice shown in this diagram is the placement of the CMS on a system external to the blade enclosure so that it can remain functional for managing other systems in the environment in the event the blade enclosure is unavailable due to some firmware update operations requiring the entire enclosure to be down or a power failure of the enclosure.
Advantages and LimitationsThis configuration has the following advantages and limitations:
Advantages:
∙Provides a completely
∙Internal cluster heartbeat network can be configured using Virtual Connect to eliminate additional network cabling and switches
∙Provides consistent management of server profiles using Virtual Connect with all cluster nodes within the blade enclosure
Limitations:
∙The blade enclosure is a single point of failure that can cause the entire cluster to go down
∙There are no nodes external to the cluster to failover workloads in the event of planned enclosure maintenance (e.g., Virtual Connect and / or Onboard Administrator firmware upgrades that require all blades in the enclosures to be shutdown)
Clustering across Multiple Blade Enclosures or non-Blade Servers
One architecture design for improving a “cluster in a box” configuration is to split the Serviceguard cluster nodes between multiple blade enclosures or other external Serviceguard cluster nodes to avoid having a single enclosure as a single point of failure (SPOF). Figure 13 is an example of this architecture with a Serviceguard cluster spanning multiple c7000 blade enclosures.
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