diff --git a/_topic_maps/_topic_map.yml b/_topic_maps/_topic_map.yml index 505feebaee..6840319d90 100644 --- a/_topic_maps/_topic_map.yml +++ b/_topic_maps/_topic_map.yml @@ -4538,6 +4538,8 @@ 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 diff --git a/modules/virt-tested-maximums.adoc b/modules/virt-tested-maximums.adoc new file mode 100644 index 0000000000..f100b9b159 --- /dev/null +++ b/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`. diff --git a/virt/about_virt/virt-supported-limits.adoc b/virt/about_virt/virt-supported-limits.adoc new file mode 100644 index 0000000000..924aadf184 --- /dev/null +++ b/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] \ No newline at end of file