Implement high-availability solutions with HP Instant Capacity - easily and effectively

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Introduction
Most enterprises like yours today depend on mission-critical applications to run their businesses. Traditionally,
mission-critical applications require high levels of availability, which has proven expensive because of the need for
redundancy, particularly for standby servers. Today, IT managers are challenged by the need to reduce budgets while
still delivering services needed to run the business. HP understands this problem and has developed products that make
high availability more cost-effective.
The key to meeting the need is virtualizationpooling and sharing of resources so that supply meets demand optimally
and automatically. HP Instant Capacity (iCAP) is a component of all the HP-UX Operating Environment bundles and has
several features that can reduce the cost of high availability. The newest addition to the iCAP program on HP Integrity
Superdome 2, HP Global Instant Capacity (GiCAP), offers improved flexibility and utilization of your existing resources. In
addition, mission-critical and business-critical applications often require high availability to maintain service-level
objectives (SLOs). Using GiCAP with the HP Serviceguard suite of high-availability solutions can help you maximize server
resource utilization and reduce the total cost of ownership while providing protection for your applications.
This paper illustrates how GiCAP can provide cost-effective, business-continuity solutions. This paper also provides
an overview of HP Serviceguard and a description of traditional high-availability solutions and configurations,
as well as how to use GiCAP and Serviceguard together. Some knowledge of HP Serviceguard and GiCAP is helpful, but
not required.
Unless otherwise specified in this document, “server” refers to HP Integrity Superdome 2 Server, and “partition” refers
to either a hard partition of the server (nPar) or a virtual partition (vPar) within the hard partition.
HP iCAP program overview
iCAP enables customers to adjust processing capacity (cores and memory) quickly to meet varying system demands.
It can be used to:
Load balance during periods of high utilization
Quickly replace processing capacity lost because of hardware failures
Increase capacity temporarily during periods of high utilization
The iCAP program includes three distinct functional areas:
1. iCAP for blades with processor cores and memory: enables you to deactivate underutilized resources
in one partition, and then activate unused resources in another partition to alleviate high resource demand in
that partition. The purchase of each iCAP processor includes an amount of temporary capacity known as HP Instant
Access Capacity (IAC).
2. HP Temporary Instant Capacity (TiCAP): enables the temporary activation of additional core resources when there are
no underutilized cores elsewhere on a server that can be deactivated. TiCAP is optional and can only be utilized in an
environment that includes some iCAP components.
3. HP Global Instant Capacity (GiCAP): enables the activation of additional resources on one member of a GiCAP group
after the deactivation of resources on a different member of the group. GiCAP provides iCAP across multiple
servers, including the ability to pool TiCAP usage. GiCAP is optional and can only be utilized in an environment that
includes some iCAP components. GiCAP does not work for memory. It is an offering specific to only cores.
Each type of iCAP provides different opportunities for high-availability solutions, as discussed later in this paper.