8. vCloud Operations Control : 8.7 Availability Management : 8.7.1 Uptime SLAs
8.7.1 Uptime SLAs
VMware vCloud components support a 99.9% uptime SLA out-of-the-box. This might be sufficient for noncritical applications or applications that are inherently highly available. For vCloud, uptime SLAs typically require the following verification:
*End customer workloads are running.
*End customer workloads are accessible (via the vCloud portal, API, and remote access protocols).
In some cases, a provider (external service provider or internal IT) might want to increase the vCloud uptime SLA. VMware can only control the resiliency of its vCloud platform components and provide recommendations to mitigate single points of failure (SPOF) in the underlying infrastructure. A provider can eliminate SPOF by providing redundancy. For example:
*Redundant power sourced from multiple feeds, with multiple whips to racks, and sufficient backup battery and generator capacity.
*Redundant network components.
*Redundant storage components:
*Storage design needs to be able to handle the I/O load. Customer workloads might not be accessible under high disk latency, file locks, and so on.
*Storage design should be tied to business continuity and disaster recovery plans, possibly including array-level backups.
*Redundant server components (multiple independent power supplies, network interface cards (NICs) and, if appropriate, host bus adaptors (HBAs).
*Sufficient compute resources for a minimum of N+1 redundancy within a vSphere high availability cluster, including sufficient capacity for timely recovery.
*Redundant databases and management.
Appropriate change, incident, problem and capacity management processes must also be well defined and enforced to make sure that poor operational processes do not result in unnecessary downtime. In addition to a redundant infrastructure, everyone responsible for operating and maintaining the environment and the supporting infrastructure must be adequately trained and skilled.
For more detailed information about increasing vCloud component resiliency, refer to the “vCloud Availability Considerations” section in Architecting a VMware vCloud.