HP Instant Capacity User's Guide for Versions 8.x

Note that whenever you have more active cores than the number of purchased core usage rights,
the temporary capacity balance will be depleted as a mechanism for tracking the non-compliance
of the system, and boottime deactivation of cores may occur even when TiCAP has not been
purchased for the system.
Instant Capacity Cell Board
Instant Capacity Cell Board offers a way to have additional (inactive) cell board capacity for your
system. These Instant Capacity cell boards, which contain memory and cores, can be activated
after a cell RTU codeword is obtained from the HP Utility Pricing Solutions portal and is applied
to the complex using the icapmodify command. You must have usage rights for all memory
attached to the cell and at least one core in order to activate a cell.
Global Instant Capacity (GiCAP)
Global Instant Capacity (GiCAP) provides HP customers with the flexibility to move usage rights
(RTUs or “Rights to Use”) for Instant Capacity components within a group of servers. It also
provides “pooled” temporary capacity across the group. This has several potential benefits:
cost-effective high availability, more adaptable load balancing, and more efficient and easier use
of temporary capacity.
For example, in case of planned or unplanned downtime, a customer can transfer usage rights
(RTUs) from a failed partition on one server to one or more other servers in the group that are
providing backup availability, thus allowing additional activations of iCAP components on the
backup servers. Without GiCAP, the only way to provide this failover scenario is to provision
each server with an adequate amount of temporary capacity in case of potential failures.
A similar scenario exists for load balancing. Rather than using temporary capacity whenever a
server is overloaded (peak profiles for all workloads on a server), usage rights (RTUs) can be
transferred from other servers in the GiCAP group that have extra capacity. These borrowed
usage rights enable new component activations on the overloaded system.
Pooled temporary capacity for a group of servers is more efficient because all temporary capacity
is available to all servers in the GiCAP group. It is also easier to manage if it is determined that
temporary capacity only needs to be applied to one member of the group and monitored across
the group instead of monitoring TiCAP for each member complex.
GiCAP Groups
Global Instant Capacity is built on the concept of a server group, or GiCAP group. The group
consists of a list of server complexes that are allowed to share Instant Capacity usage rights (for
cores, cell boards, and memory) and temporary capacity. There are no particular constraints on
the number of servers allowed to be in a group, but there are grouping rules defined by HP to
specify the types of servers allowed to group together.
GiCAP Group Manager
For each group, an HP-UX system must be designated as the Global Instant Capacity Group
Manager. It is this system which maintains information about the group, group resources, and
the grouping rules. icapmanage commands are intended to be invoked only on a Group Manager
system to manage one or more GiCAP groups.
The Group Manager must be an HP-UX system running the Instant Capacity software version
8.01.01 or later. The system running the Group Manager does not need to have any Instant
Capacity components, nor does it need to be a partitionable system. The system must have a
machine-readable serial number, as displayed by the shell command getconf
CS_MACHINE_SERIAL. It is recommended that the Group Manager not be on a partition that is
a member of any GiCAP group. If run on a partitionable system, changing the configuration of
the partitions may result in the GiCAP Manager becoming inoperative.
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