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CPU hot plugging in Openstack

asked 2016-03-02 03:32:51 -0500

Awais gravatar image

updated 2016-03-09 07:23:28 -0500

Does Openstack support CPU hot plug feature. For example if I already have a VM with 2 vcpu's and I want to increase its vcpu's to 4 or any other number (both cases up-scale or down-scale). Can it be done using the latest version of Openstack (Liberty). I don't see any API call that serves that purpose. If anyone knows if this feature is currently available or is it under development.

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answered 2016-03-09 09:21:04 -0500

Bipin gravatar image

I hope you are looking for the following

nova resize myinstance 4 --poll

Here nova will upgrade the VM from a small flavor to high flavor. Assume that this instance is running on m1.small with an ID 2. Now we are resizing it to next high flavor which having ID 4. By default, the nova resize command gives the guest operating system a chance to perform a controlled shutdown before the instance is powered off and the instance is resized. The shutdown behavior is configured by the shutdown_timeout parameter that can be set in the nova.conf file. Its value stands for the overall period (in seconds) a guest operation system is allowed to complete the shutdown.

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that would be a cold plug and not a hot plug.

lufaxo gravatar imagelufaxo ( 2016-03-09 13:26:47 -0500 )edit

I knew about that @Bipin, Actually if VM is running and we do not want to have a downtime of even a second, in that case hot-plugging is used, it increases the performance at run time. I have done this using libvirt but I am not aware if this can be done in Openstack. Though its an important feature

Awais gravatar imageAwais ( 2016-03-10 07:16:43 -0500 )edit

Got it, I understand it otherway

Bipin gravatar imageBipin ( 2016-03-12 01:56:25 -0500 )edit

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Asked: 2016-03-02 03:32:51 -0500

Seen: 737 times

Last updated: Mar 09 '16