Openstack related quieries

Sean Mooney smooney at redhat.com
Mon Dec 14 21:14:08 UTC 2020


On Mon, 2020-12-14 at 11:29 +0530, Gokul Kalal wrote:
> Hi All, here are the few questionnaires for which I am looking for answers.
> It would be of great help if anybody provides their suggestions on the
> below questions.
> 
> 1. Is RT enabled KVM available for Openstack? It would be helpful if anyone
> provides a link for the same?
yes nova support enableing realtime instsantce on kvm via libvirt as of the mitaka release
https://specs.openstack.org/openstack/nova-specs/specs/mitaka/implemented/libvirt-real-time.html

this can be enabled via nova flavor extra_specs
https://docs.openstack.org/nova/latest/user/flavors.html#extra-specs-realtime-policy

> 2. Is Openstack using devstack preferable in production or it is meant only
> for the dev setup?
devstack is intend solely for devleopemnt and should not be used outside of a test envionrment
it does not directly support upgrade and other mantaicne operation like host reboots :)

in the distant past of openstack there were some who used devstack in production but unless
your a developer working on openstack you should not use devstack.


> 3. For RT KVM, Is hyper-threading preferred?
generally it is not but it depend on your workload.

> 4. What are the minimum system requirements for openstack setup?
our vms that are avaiable in the CI system have 8 cores and 8GB of ram and 80GB of disk.

i have ran a 4 node test deployment with devstack on my laptop which has 
32GB of ram and a quad core  Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz

> (Currently, I am equipped with Quad-Core i7-8559U with 16 GB RAM, will this
> work for Openstack setup? My requirements are 3 VMs, out of which 2 VM will
> be having dedicated 3 CPU cores allocated(hyperthreading enabled) and host
> ubuntu and another VM will be running on the remaining 2 cores - isolcpu
> used to isolate cores).

sure for a dev setup that should be fine. depending on what services you want to run you cna run a contoler/all-in-one
node on 6GB of ram 8G is recommended, compute nodes can run on 2-4G depending on how much space you want to keep for nested vms.

for a production deployment you will want something more substantial but for devleopment you can get by with a few intel nucs or old laptops.
you could with some work even get openstack running on a few raspbery pi 4 boards butthe lack of hardware virualisation support means the vms you boot
would be quite slow.
if your planning to work on project other then nova then that might not be a consern openstack scalse down pretty well so you dont need to have a
datacenter to develop it. personally i do most of my dev in 8G vms on a home openstack deployment.
by the way we have 80G of space on the ci vms for logs and other reason. you can install on a ubuntu vm with 20G of disk or less in some cases, if you
want cinder you will need more space for it to manage similar for swift but as i said the requiremnt tend to scale based on what you want to deploy
and use.


> 





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