Description of problem:Trying to bring up aws cluster on custom mtu say 1600 but i see it comes on default uplink mtu of 8901. Version-Release number of selected component (if applicable):4.4.0-0.ci-2020-01-21-134224 How reproducible:Always Steps to Reproduce: 1.Add mtu in install-config.yml metadata: creationTimestamp: null name: qe-anusaxen networking: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23 machineNetwork: - cidr: 10.0.0.0/16 networkType: OpenShiftSDN mtu: 1600 serviceNetwork: - 172.30.0.0/16 platform: aws: 2. ./openshift-install create cluster 3. ocnkube-config also reflects 8901 mtu # oc get cm ovnkube-config -n openshift-ovn-kubernetes -oyaml | grep -i mtu mtu="8901" Actual results: Cluster comes default on 8901 uplink mtu Expected results: expecting mtu to be 1600 Additional info: Let me know if i am mising something in configuration
*Typo's networkType was OVNKUbernetes with that mtu value and ocnkube-config=ovnkube-config
> 1. Add mtu in install-config.yml install-config doesn't allow configuring MTU... you need to create a network operator config, as with https://docs.openshift.com/container-platform/4.2/installing/installing_aws/installing-aws-network-customizations.html#modifying-nwoperator-config-startup_installing-aws-network-customizations, but using "type: OVNKubernetes" and "ovnKubernetesConfig:"
(In reply to Dan Winship from comment #2) > > 1. Add mtu in install-config.yml > > install-config doesn't allow configuring MTU... you need to create a network > operator config, as with > https://docs.openshift.com/container-platform/4.2/installing/installing_aws/ > installing-aws-network-customizations.html#modifying-nwoperator-config- > startup_installing-aws-network-customizations, but using "type: > OVNKubernetes" and "ovnKubernetesConfig:" Hi Dan, thanks for confirming that. I initially tried it openshift-sdn way like creating cluster-network-03-config.yml that was consumed during create cluster but did't see it working. >> cluster-network-03-config.yml apiVersion: operator.openshift.io/v1 kind: Network metadata: name: cluster spec: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23 serviceNetwork: - 172.30.0.0/16 defaultNetwork: type: OVNKubernetes ovnKubernetesConfig: mtu: 1600 But i believe its working for Phil the install-config.yml way as per discussion on Forum-sdn so gave a try to that way too. Let me try creating x-x-03-config.yml and see again. Thanks. I am sure the right way is x-x-03-config.yml but not sure how its working for Phil. Phil, any comments?
@anurag Please look try oc logs -c ovnkube-master ovnkube-master-XXXX | grep "Default:{MTU:" where XXXX is the pod. Also oc get cm ovnkube-config -n openshift-ovn-kubernetes -oyaml | grep "^data:" -A17
@anurag is this ready to be closed? Anything left to do?
@Phil, thanks for asking. If comment 5 steps seems okay to you, we can close this. I believe you tested install-config way so just wondering.
@anurag Steps in comment 5 are fine by me. I think I accidentally picked 9001 that were converted into 8901 and I didn't spot what was really happening. The task is to be able to pick a different (unexpected) mtu at install and see it applied in the cluster. The instructions on how to do that are not part of the requirement. You have shown that it works so that proves it.
Thanks @Phil for confirming the steps. We can close this bug.
Not a bug. This works when using the correct procedure for creating the ovn cluster.