4.18 rel notes for multiple subnet features and known issues

release_notes/ocp-4-18-release-notes.adoc

@@ -554,7 +554,7 @@ For more information about configuring machine types, see xref:../installing/ins
 
 [id="ocp-4-18-installation-and-update-gcp-byo-vpc-phz_{context}"]
 ==== Provide your own private hosted zone when installing a cluster on {gcp-full}
-With this release, you can provide your own private hosted zone when installing a cluster on {gcp-short} into a shared VPC. If you do, the requirements for the bring your own (BYO) zone are that the zone must use a DNS name such as `<cluster name>.<base domain>.` and that you bind the zone to the VPC network of the cluster.
+With this release, you can provide your own private hosted zone when installing a cluster on {gcp-short} into a shared VPC. If you do, the requirements for the bring your own (BYO) zone are that the zone must use a DNS name such as `<cluster_name>.<base_domain>.` and that you bind the zone to the VPC network of the cluster.
 
 For more information, see xref:../installing/installing_gcp/installing-gcp-shared-vpc.adoc#installation-gcp-shared-vpc-prerequisites_installing-gcp-shared-vpc[Prerequisites for installing a cluster on GCP into a shared VPC] and xref:../installing/installing_gcp/installing-gcp-user-infra-vpc.adoc#prerequisites[Prerequisites for installing a cluster into a shared VPC on GCP using Deployment Manager templates].
 
@@ -572,12 +572,20 @@ You can now deploy single-stack IPv6 clusters on {rh-openstack}.
 You must configure {rh-openstack} prior to deploying your {product-title} cluster. For more information, see xref:../installing/installing_openstack/installing-openstack-installer-custom.adoc#installation-configuring-shiftstack-single-ipv6_installing-openstack-installer-custom[Configuring a cluster with single-stack IPv6 networking].
 
 [id="ocp-4-18-installation-and-update-nutanix-multiple-nics_{context}"]
-==== Installing a cluster on Nutanix with up to 32 subnets
-With this release, Nutanix supports more than one subnet for the Prism Element where you deployed an {product-title} cluster to. A maximum of 32 subnets for each Prism Element is supported.
+==== Installing a cluster on Nutanix with multiple subnets
+With this release, you can install a Nutanix cluster with more than one subnet for the Prism Element into which you are deploying an {product-title} cluster. 
 
 For more information, see xref:../installing/installing_nutanix/installing-nutanix-installer-provisioned.adoc#installation-configuring-nutanix-failure-domains_installing-nutanix-installer-provisioned[Configuring failure domains] and xref:../installing/installing_nutanix/installation-config-parameters-nutanix.adoc#installation-configuration-parameters-additional-nutanix_installation-config-parameters-nutanix[Additional Nutanix configuration parameters].
 
-For an existing Nutanix cluster, you can add multiple subnets by using machine sets. For more information, see xref:../installing/installing_nutanix/nutanix-failure-domains.adoc#post-installation-configuring-nutanix-failure-domains_nutanix-failure-domains[Adding failure domains to the Infrastructure CR].
+For an existing Nutanix cluster, you can add multiple subnets by using xref:../machine_management/creating_machinesets/creating-machineset-nutanix.adoc#machineset-yaml-nutanix_creating-machineset-nutanix[compute] or xref:../machine_management/control_plane_machine_management/cpmso_provider_configurations/cpmso-config-options-nutanix.adoc#cpmso-yaml-provider-spec-nutanix_cpmso-config-options-nutanix[control plane] machine sets.
+
+[id="ocp-4-18-installation-and-update-vsphere-multiple-nics_{context}"]
+==== Installing a cluster on {vmw-full} with multiple network interface controllers (Technology Preview)
+With this release, you can install a {vmw-full} cluster with multiple network interface controllers (NICs) for a node.
+
+For more information, see xref:../installing/installing_vsphere/ipi/installing-vsphere-installer-provisioned-network-customizations.adoc#installation-vsphere-multiple-nics_installing-vsphere-installer-provisioned-network-customizations[Configuring multiple NICs].
+
+For an existing {vmw-short} cluster, you can add multiple subnets by using xref:../machine_management/creating_machinesets/creating-machineset-vsphere.adoc#machineset-vsphere-multiple-nics_creating-machineset-vsphere[compute machine sets].
 
 [id="ocp-release-notes-agent-5-node-control-plane_{context}"]
 ==== Configuring 4 and 5 node control planes with the Agent-based Installer
@@ -1922,6 +1930,11 @@ In the following tables, features are marked with the following statuses:
 |Not Available
 |Not Available
 |General Availability
+
+|Installing a cluster on {vmw-full} with multiple network interface controllers
+|Not Available
+|Not Available
+|Technology Preview
 |====
 
 [discrete]
@@ -1999,6 +2012,11 @@ In the following tables, features are marked with the following statuses:
 |Removed
 |Removed
 
+|Adding multiple subnets to an existing {vmw-full} cluster by using compute machine sets
+|Not Available
+|Not Available
+|Technology Preview
+
 |====
 
 [discrete]
@@ -2416,6 +2434,23 @@ In the following tables, features are marked with the following statuses:
 
 * A regression in the behaviour of `libreswan` caused some nodes with IPsec enabled to lose communication with pods on other nodes in the same cluster. To resolve this issue, consider disabling IPsec for your cluster. (link:https://issues.redhat.com/browse/OCPBUGS-43713[*OCPBUGS-43713*])
 
+* There is a known issue in {product-title} version 4.18 that prevents configuring multiple subnets in the failure domain of a Nutanix cluster during installation.
+There is no workaround for this issue.
+(link:https://issues.redhat.com/browse/OCPBUGS-49885[*OCPBUGS-49885*])
+
+ * The following known issues exist for configuring multiple subnets for an existing Nutanix cluster by using a control plane machine set:
++
+-- 
+** Adding subnets above the existing subnet in the `subnets` stanza causes a control plane node to become stuck in the `Deleting` state.
+As a workaround, only add subnets below the existing subnet in the `subnets` stanza.
+
+** Sometimes, after adding a subnet, the updated control plane machines appear in the Nutanix console but the {product-title} cluster is unreachable.
+There is no workaround for this issue.
+-- 
++
+These issues occur on clusters that use a control plane machine set to configure subnets regardless of whether subnets are specified in a failure domain or the provider specification.
+(link:https://issues.redhat.com/browse/OCPBUGS-50904[*OCPBUGS-50904*]) 
+
 * There is a known issue with {op-base-system} 8 worker nodes that  use `cgroupv1` Linux Control Groups (cgroup). The following is an example of the error message displayed for impacted nodes: `UDN are not supported on the node ip-10-0-51-120.us-east-2.compute.internal as it uses cgroup v1.` As a workaround, users should migrate worker nodes from `cgroupv1` to `cgroupv2`. (link:https://issues.redhat.com/browse/OCPBUGS-49933[*OCPBUGS-49933*])
 
 * The current PTP grandmaster clock (T-GM) implementation has a single National Marine Electronics Association (NMEA) sentence generator sourced from the GNSS without a backup NMEA sentence generator. If NMEA sentences are lost before reaching the e810 NIC, the T-GM cannot synchronize the devices in the network synchronization chain and the PTP Operator reports an error. A proposed fix is to report a `FREERUN` event when the NMEA string is lost. Until this limitation is addressed, T-GM does not support PTP clock holdover state. (link:https://issues.redhat.com/browse/OCPBUGS-19838[*OCPBUGS-19838*])