Synnefo » snf-ganeti

Global hypervisor parameters

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Current State and shortcomings

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Currently all hypervisor parameters are modifiable both globally

(cluster level) and at instance level. However, there is no other

framework to held hypervisor-specific parameters, so if we want to add

a new class of hypervisor parameters that only makes sense on a global

level, we have to change the hvparams framework.

Proposed changes

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We add a new (global, not per-hypervisor) list of parameters which are

not changeable on a per-instance level. The create, modify and query

instance operations are changed to not allow/show these parameters.

Furthermore, to allow transition of parameters to the global list, and

to allow cleanup of inadverdently-customised parameters, the

``UpgradeConfig()`` method of instances will drop any such parameters

from their list of hvparams, such that a restart of the master daemon

is all that is needed for cleaning these up.

Also, the framework is simple enough that if we need to replicate it

at beparams level we can do so easily.