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resizing the hypervisor or compute host

asked 2019-07-02 13:09:07 -0500

phil111 gravatar image

how to resize an openstack hypervisor or compute host on a live OpenStack cloud. especially for vCPUs. because beyond what my host hardware can give (4 cpus) i am failing to launch any further instances. see caption attached for usage.

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You forgot to attach something.

You can change the virtual CPUs exposed by nodes using scheduler weights. This is a global value, but it can also be associated with host aggregates since Stein, though not single hosts.

Bernd Bausch gravatar imageBernd Bausch ( 2019-07-02 18:28:21 -0500 )edit

Host aggregate multipliers are explained in the corresponding spec. Not sure if the admin documentation has been updated yet.

Bernd Bausch gravatar imageBernd Bausch ( 2019-07-02 18:30:42 -0500 )edit

Thanks Bernd for the feedback. I failed to upload because of the >10 points limit. However it was the hypervisors and compute host utilisation. It seems to be picking the details from my lab workstation specs but only for the CPUs and RAM. As for the storage it pics some lower value.

phil111 gravatar imagephil111 ( 2019-07-03 02:33:12 -0500 )edit

This is why I would like to adjust the values or add a new compute host. This will require the two compute nodes OpenStack instances to communicate with each other- not sure this is possible in "Stein"

phil111 gravatar imagephil111 ( 2019-07-03 02:36:14 -0500 )edit

What do you mean by “communicate with each other”? Instances can access each other via the network no matter on which compute host they run. In fact, the compute host is not visible to normal users.

I don’t know how available storage is determined and why it’s low in your case.

Bernd Bausch gravatar imageBernd Bausch ( 2019-07-03 09:31:59 -0500 )edit

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answered 2019-07-05 00:13:13 -0500

Vinoth gravatar image

if you want to scale up the physical hypervisor, you need to bring it down and increase the resources you want such as RAM and Disk space.

In case you want to adjust the vCPUs for VM provisioning, you can look for changing the overcommit ratio for CPU in nova.conf file and restart the nova-compute service on the fly.

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Thanks Vinoth. Still failing to access the particular file to make the changes.

Summary of the error message is below:

Error: Failed to perform requested operation on instance "sw8", the instance has an error status: Please try again later [Error: Exceeded maximum number of retries. Exhausted all

phil111 gravatar imagephil111 ( 2019-07-09 04:54:04 -0500 )edit

I made the changes and on one cloud it worked. On the other cloud setup, I am getting this error message Message No valid host was found. Code 500 Details File "/usr/lib/python2.7/dist-packages/nova/conductor/", line 1145, in schedule_and_build_instances instance_uuids, return_alternates=T

phil111 gravatar imagephil111 ( 2019-07-12 03:27:09 -0500 )edit

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Asked: 2019-07-02 13:09:07 -0500

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Last updated: Jul 05 '19