CNV#52378: supported limits kbase info

Author: ousleyp

_topic_maps/_topic_map.yml

@@ -4522,6 +4522,8 @@ Topics:
   - Name: About OKD Virtualization
     File: about-virt
     Distros: openshift-origin
+  - Name: Supported limits
+    File: virt-supported-limits
   - Name: Security policies
     File: virt-security-policies
   - Name: Architecture

modules/virt-tested-maximums.adoc

@@ -0,0 +1,66 @@
+// Module included in the following assemblies:
+//
+// * virt/about_virt/virt-supported-limits.adoc
+
+:_mod-docs-content-type: REFERENCE
+[id="virt-tested-maximums_{context}"]
+= Tested maximums for {VirtProductName}
+
+The following limits apply to a large-scale {VirtProductName} 4.x environment. They are based on a single cluster of the largest possible size. When you plan an environment, remember that multiple smaller clusters might be the best option for your use case.
+
+[id="vm-maximums_{context}"]
+== Virtual machine maximums
+
+The following maximums apply to virtual machines (VMs) running on {VirtProductName}. These values are subject to the limits specified in link:https://access.redhat.com/articles/rhel-kvm-limits[Virtualization limits for Red Hat{nbsp}Enterprise Linux with KVM].
+
+[cols="1,1,1",subs="attributes+"]
+|===
+|Objective (per VM) |Tested limit |Theoretical limit
+
+|Virtual CPUs |216 vCPUs |255 vCPUs
+|Memory |6 TB |16 TB
+|Single disk size |20 TB |100 TB
+|Hot-pluggable disks |255 disks |N/A
+|===
+
+[NOTE]
+====
+Each VM must have at least 512 MB of memory.
+====
+
+[id="host-maximums_{context}"]
+== Host maximums
+
+The following maximums apply to the {product-title} hosts used for {VirtProductName}.
+
+[cols="1,1,1",subs="attributes+"]
+|===
+|Objective (per host) |Tested limit |Theoretical limit
+
+|Logical CPU cores or threads |Same as {op-system-base-full} |N/A
+|RAM |Same as {op-system-base} |N/A
+|Simultaneous live migrations |Defaults to 2 outbound migrations per node, and 5 concurrent migrations per cluster |Depends on NIC bandwidth
+|Live migration bandwidth |No default limit |Depends on NIC bandwidth
+|===
+
+[id="cluster-maximums_{context}"]
+== Cluster maximums
+
+The following maximums apply to objects defined in {VirtProductName}.
+
+[cols="1,1,1",subs="attributes+"]
+|===
+|Objective (per cluster) |Tested limit |Theoretical limit
+
+|Number of attached PVs per node |N/A |CSI storage provider dependent
+|Maximum PV size |N/A |CSI storage provider dependent
+|Hosts |500 hosts (100 or fewer recommended) ^[1]^ |Same as {product-title}
+|Defined VMs |10,000 VMs ^[2]^ |Same as {product-title}
+|===
+. If you use more than 100 nodes, consider using {rh-rhacm-first} to manage multiple clusters instead of scaling out a single control plane. Larger clusters add complexity, require longer updates, and depending on node size and total object density, they can increase control plane stress.
++
+Using multiple clusters can be beneficial in areas like per-cluster isolation and high availability.
+. The maximum number of VMs per node depends on the host hardware and resource capacity. It is also limited by the following parameters:
+
+* Settings that limit the number of pods that can be scheduled to a node. For example: `maxPods`.
+* The default number of KVM devices. For example: `devices.kubevirt.io/kvm: 1k`.

virt/about_virt/virt-supported-limits.adoc

@@ -0,0 +1,21 @@
+:_mod-docs-content-type: ASSEMBLY
+[id="virt-supported-limits"]
+= Supported limits
+include::_attributes/common-attributes.adoc[]
+:context: virt-supported-limits
+
+toc::[]
+
+You can refer to tested object maximums when planning your {product-title} environment for {VirtProductName}. However, approaching the maximum values can reduce performance and increase latency. Ensure that you plan for your specific use case and consider all factors that can impact cluster scaling.
+
+For more information about cluster configuration and options that impact performance, see the link:https://access.redhat.com/articles/6994974[{VirtProductName} - Tuning & Scaling Guide] in the Red{nbsp}Hat Knowledgebase.
+
+include::modules/virt-tested-maximums.adoc[leveloffset=+1]
+
+[role="_additional-resources"]
+[id="additional-resources_{context}"]
+== Additional resources
+* link:https://access.redhat.com/articles/6994974[{VirtProductName} - Tuning & Scaling Guide]
+* xref:../../scalability_and_performance/planning-your-environment-according-to-object-maximums.adoc#planning-your-environment-according-to-object-maximums[Planning your environment according to object maximums]
+* xref:../../nodes/nodes/nodes-nodes-managing-max-pods.adoc#nodes-nodes-managing-max-pods[Managing the maximum number of pods per node]
+* link:https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes[{rh-rhacm-title} documentation]