A running vm cannot dynamically scale cpu and memory. It can be expanded when stopped

[1450793561]

Questrion:

A running vm cannot dynamically scale cpu and memory.It's done when stopped

log detail

2022-11-02 14:44:13,311 INFO  [c.c.c.ClusterManagerImpl] (Cluster-Heartbeat-1:ctx-57dd945c) (logid:00501acf) Management node 1 is detected inactive by timestamp but is pingable
2022-11-02 14:44:13,629 DEBUG [c.c.a.ApiServlet] (qtp1462044018-848:ctx-5aeed521) (logid:1b967db1) ===START===  10.10.130.13 -- GET  virtualmachineid=beb97c61-bf41-4b38-ad74-1c65f6c5b125&keyword=&page=1&pageSize=10&details=min&response=json&command=listServiceOfferings
2022-11-02 14:44:13,649 DEBUG [c.c.a.ApiServer] (qtp1462044018-848:ctx-5aeed521 ctx-f8220033) (logid:1b967db1) CIDRs from which account 'Acct[2135826d-4dcd-11ed-89f1-02e685806f48-admin] -- Account {"id": 2, "name": "admin", "uuid": "2135826d-4dcd-11ed-89f1-02e685806f48"}' is allowed to perform API calls: 0.0.0.0/0,::/0
2022-11-02 14:44:13,663 WARN  [c.c.a.d.ParamGenericValidationWorker] (qtp1462044018-848:ctx-5aeed521 ctx-f8220033) (logid:1b967db1) Received unknown parameters for command listServiceOfferings. Unknown parameters : details

[DaanHoogland]

yes @1450793561 , this is a known limitation. I thought we had made sure the button was greyed or even omitted when the VM is running. What version did you encounter this with?

[1450793561]

@DaanHoogland

CloudStack 4.17.1.0,Is there a repair plan?

[DaanHoogland]

@1450793561 I don´t know if it is on someones schedule, so i'm afraid not.

[1450793561]

yeh,ok

[weizhouapache]

@1450793561
as @DaanHoogland mentioned, this is a known limitation, introduced by #4878
the UI change was introduced in #5923

        if (vmHypervisorType.equals(HypervisorType.KVM) && !currentServiceOffering.isDynamic()) {
            String message = String.format("Unable to live scale VM on KVM when current service offering is a \"Fixed Offering\". KVM needs the tag \"maxMemory\" to live scale and it is only configured when VM is deployed with a custom service offering and \"Dynamic Scalable\" is enabled.");
            s_logger.info(message);
            throw new InvalidParameterValueException(message);

maybe @GutoVeronezi can have a look to see if it is possible to improve it in the future.
for example, scale a running vm on kvm from a fixed offering to another fixed offering

[GutoVeronezi]

Hello @1450793561 @weizhouapache

KVM requires defining ranges for CPU and memory in the VM XML to allow the VM to be dynamically scaled. Currently, those ranges are set only when working with custom compute offerings. For custom-constrained offerings, the ranges are defined while creating them; for custom-unconstrained offerings, the ranges are defined via the global settings vm.serviceoffering.cpu.cores.max and vm.serviceoffering.ram.size.max, or, if the settings are 0, they are defined according to the host capacities.

As KVM supports dynamic scaling, this situation is a matter of designing the logical solution in ACS. We are planning to extend ACS to allow dynamic scaling VMs with fixed offerings in KVM; however, we do not have a due date yet.

---

@1450793561, while a VM with fixed offering cannot be dynamically scaled yet, you could try using custom offerings. Along with the custom offerings, some configurations have to be done:

• in the global settings, enable.dynamic.scale.vm must be true;
• the template and the VM must be marked as Dynamically scalable;

VMs started after setting those configurations will be able to be dynamically scaled. If you have any doubts or issues using this alternative, just ping me in this issue.

[weizhouapache]

Hello @1450793561 @weizhouapache

KVM requires defining ranges for CPU and memory in the VM XML to allow the VM to be dynamically scaled. Currently, those ranges are set only when working with custom compute offerings. For custom-constrained offerings, the ranges are defined while creating them; for custom-unconstrained offerings, the ranges are defined via the global settings vm.serviceoffering.cpu.cores.max and vm.serviceoffering.ram.size.max, or, if the settings are 0, they are defined according to the host capacities.

As KVM supports dynamic scaling, this situation is a matter of designing the logical solution in ACS. We are planning to extend ACS to allow dynamic scaling VMs with fixed offerings in KVM; however, we do not have a due date yet.

@1450793561, while a VM with fixed offering cannot be dynamically scaled yet, you could try using custom offerings. Along with the custom offerings, some configurations have to be done:

• in the global settings, enable.dynamic.scale.vm must be true;
• the template and the VM must be marked as Dynamically scalable;

VMs started after setting those configurations will be able to be dynamically scaled. If you have any doubts or issues using this alternative, just ping me in this issue.

Great, thanks @GutoVeronezi for your detailed explanation.
Looking forward to the improvement.

[CodeBleu]

@rohityadavcloud This is a pretty important feature and was wondering if this could be placed in a milestone and assigned?

[GutoVeronezi]

Hello @CodeBleu,

We had some other priorities in the past 2 years and, unfortunately, we were not able develop this improvement so far. However, we are planning to implement it in the next months, probably being addressed publicly on 4.21. We will update you as we make progress on this matter.

We already have some use-cases to base the improvement on; however, feel free to share your opinion on how you expect this feature to work.