Hi, Wido has given a talk "How to Re-use Old Hardware with CloudStack. Saving Money and the Environment" in CCC 2023. If you are interested, please watch the video on https://www.youtube.com/watch?v=KAJCkC00tzQ (starts at 11:41)
-Wei On Wed, Apr 10, 2024 at 5:49 PM R A <[email protected]> wrote: > > Hi, > > is it also problematic migrating to different CPUs of same Family? For > example from Epyc 9654 to Epyc 9754 ? > > So you recommend to make a cluster for each CPU Type ? Can you define the > migration peer for hosts? For example having them all one cluster but define > somehow that migration should be done between hosts of same CPU? > > BR > > -----Original Message----- > From: Guto Veronezi <[email protected]> > Sent: Mittwoch, 10. April 2024 00:14 > To: [email protected] > Subject: Re: CPU compatibility > > Hello Steve, > > For CloudStack, it does not matter if you have hosts with different > processors; however, this is a recommendation regarding how virtualization > systems work; therefore, this discussion happens aside from CloudStack. > > When we are dealing with different processors, we are dealing with different > flags, instructions, clocks, and so on. For processors of the same family, > but of different generations, we can level the instructions to the lowest > common denominator (limit the instructions to the older generation); however, > it starts to get tricky when we are dealing with different families. For > instance, if you deploy a guest VM in a host with Xeon Silver and try to > migrate it to a Xeon Gold, the OS of your guest, which already knows the Xeon > Silver instructions, might not adapt to the instructions of the new host > (Xeon Gold). Therefore, in these cases, you will face problems in the guest > VM. > > If you are aware of the differences between the processors and that mixing > different types can cause problems, then you can create a cluster mixing > them; however, it is not recommended. > > For KVM, the parameter is defined in ACS; on the other hand, for XenServer > and VMware this kind of setup is done in the cluster in XenServer or vCenter. > > It is also important to bear in mind that, even though you level the > instruction sets between the different processors in the host operating > system, you might still suffer some issues due to clock differences when you > migrate a VM from a faster CPU to a slower CPU and vice versa. > > Best regards, > Daniel Salvador (gutoveronezi) > > On 09/04/2024 18:58, Wei ZHOU wrote: > > Hi, > > > > You can use a custom cpu model which is supported by both cpu processors. > > > > Please refer to > > https://docs.cloudstack.apache.org/en/latest/installguide/hypervisor/k > > vm.html#configure-cpu-model-for-kvm-guest-optional > > > > -Wei > > > > > > On Tuesday, April 9, 2024, S.Fuller <[email protected]> wrote: > > > >> The Cloudstack Install Guide has the following statement - "All hosts > >> within a cluster must be homogenous. The CPUs must be of the same > >> type, count, and feature flags" > >> > >> Obviously this means we can't mix Intel and AMD CPUs within the same > >> cluster. However, for a cluster with Intel CPUs, how much if any > >> leeway is there within this statement? If I have two 20 Core Xeon > >> Silver 4316 CPUs on one host and two 20 Core Xeon Silver 4416 CPUs > >> in another, is that close enough? I'm looking to add capacity to an > >> existing cluster, and am trying to figure out how "picky" Cloudstack is > >> about this. > >> > >> > >> > >> Steve Fuller > >> [email protected] > >>
