HP Insight Orchestration 6.3 User Guide

Automated allocation
Allocation is the process of finding the resources to match to the logical objects described in a
template. An Insight Orchestration template is the logical specification of an infrastructure service
using template components known as logical objects, enabling the user to provision an infrastructure
service from resources.
In Insight Orchestration templates, logical objects are specified either by attribute value or by
name. Logical server groups and storage are specified by attribute value, and networks are specified
by name or attribute. The process of matching logical objects to resources is a key capability of
Insight Orchestration and is part of several request types, including Create Service request.
After validating the arguments of a Create Service request, the Insight Orchestration controller
performs an allocation. If Insight Orchestration can locate the resources that match the template,
then the allocation is successful. After a successful match, Insight Orchestration reserves the selected
resources and provisions to instantiate the infrastructure service specified by the template. If Insight
Orchestration does not locate the necessary resources, the request fails, the resources are not
reserved, and the infrastructure service is not created.
Insight Orchestration can also utilize the allocation process during the provisioning process. This
internal allocation process can begin when Insight Orchestration cannot successfully provision a
logical sever. Insight Orchestration releases the allocated server and attempts another allocation
to find a replacement server and continue the provisioning. If the reallocation fails, the Create
request fails.
If you view logical resources in isolation, Insight Orchestration might not be able to successfully
allocate the template. Insight Orchestration cannot allocate a network without successfully allocating
the logical server groups connected to that network. Similarly, Insight Orchestration cannot allocate
logical server groups without successfully allocating the storage for all the servers within the group.
When Insight Orchestration executes the allocation algorithm to search for resources, it attempts
to allocate networks, then logical server groups, and finally storage. To maximize the chances of
success, within each category, the allocation algorithm always attempts to allocate the most
constrained logical object first. For example, all the networks in a template are evaluated, and the
network with the smallest number of candidate subnets is chosen to allocate first.
A Virtual Connect Domain Group defines the boundaries for a set of resources, specifically servers,
networks, and SAN volumes. Any resource within a VC Domain Group is visible to or connected
to any other resource within the same VC Domain Group. However, connectivity between VC
Domain Groups is uncertain. The Insight Orchestration algorithm verifies VC Domain group
boundaries by backtracking, incrementally building candidate solutions for allocation, and
abandoning each partial candidate as soon as it determines that it cannot possibly complete the
allocation. If the subnet does not have enough servers attached to the network associated to the
VC Domain Group, the subnet allocated to a network is abandoned. Insight Orchestration chooses
another candidate subnet and retries the logical server group allocation. If another valid candidate
subnet is not located, the allocation process fails, and all partial reservations are released.
Allocation takes place within the context of multiple Create Service requests submitted simultaneously.
If two allocations occur at the same time, they might fail. This occurs if users provision a solution
using the same resources at the same time. Consequently, Insight Orchestration treats allocation
as a critical section to ensure only one allocation occurs at a time.
Automated operating system provisioning
Insight Orchestration's automated operating system provisioning supports either SAN boot or DAS
boot on a server blade, but not both. When configured for boot from SAN, the internal hard drive
must be disabled. Insight Orchestration supports DAS boot with or without SAN data, but does
not support SAN boot with DAS data.
Insight Orchestration supports SAN boot or DAS boot OS deployment using Insight Control server
deployment, HP Server Automation, and Ignite-UX. With Insight Control server deployment, boot
60 Insight Orchestration provisioning and allocation