Vsan stretched cluster requirements While OCI does not offer a native or automated method for deploying a cross-region VMware vSAN stretched cluster, Oracle Cloud VMware Solution makes it possible through its unique flexibility. In this architecture, ESXi hosts would be placed in two different physical locations and join together with high bandwidth low latency networking. Stretched clusters are typically deployed in environments where the distance between data centers is limited, such as metropolitan or campus environments. Under vSAN, click Fault Domains . Verify that you have completed the Planning and Preparation Workbook with the management domain or workload domain deployment option included. Hardware Requirements The following requirements are common to all three deployment types (Standard, Two-Node, Stretched), regardless of which one is being used. As a result, guidance to achieve optimal performance in the ESA is different than recommendations found for the OSA. Choose the PATCH /v1/clusters/ {id} option. Each vSAN host must have a vSAN certified RDMA-capable NIC, as listed in the vSAN section of the VMware Compatibility Guide. Since the ESA is designed to power traditional vSAN HCI clusters and disaggregated vSAN storage clusters, the flexibility of ESA may invite non-optimal configurations when deployed as a vSAN storage cluster. Two-node vSAN Each vSAN stretched cluster requires a witness host deployed in a vSAN witness zone, which must be different from the location of both availability zones. vSAN even has durability mechanisms in place (such as durability components) that help data to remain intact and accessible over multiple disruptions. Create two VM This document explains how to size network bandwidth between sites when using vSAN HCI clusters and vSAN Max clusters in a stretched cluster configuration. In this post, I want to show you, how to deploy vSAN 8 (OSA) using “Two node vSAN cluster” option. All capacity devices, drivers, and firmware versions in your vSAN configuration must be certified and listed in the vSAN section of the VMware Compatibility Guide . Instead of using a dedicated physical ESX host as a witness host, you can deploy the vSAN witness appliance. The information includes system requirements, sizing guidelines, and suggested best practices. Architecture When selected, a vSAN Stretched Cluster is created across three AZ's, creating a vSphere Cluster that can survive the loss of entire Availability Zone. VSAN Stretched Cluster The purpose of this document is to explain how to size bandwidth requirements for Virtual SAN in Stretched Cluster configurations. You may refer to below link for vSAN stretched cluster network design and requirements. We' Comprehensive guide on vSAN Stretched Cluster and 2 Node configurations, covering setup, management, and failure scenarios. Jun 14, 2025 · The behavior during failure scenarios in vSAN stretched clusters is determined by the interaction between the Site Disaster Tolerance policy setting and the Secondary Failures to Tolerate (FTT) configuration. With modern hardware, and vSAN ESA, customers can build incredibly robust 2-Node configurations that can achieve extraordinary levels of performance. Jun 1, 2021 · Consider a multiple-stretched cluster design. If you place DRS in partially automated mode, you can control which VMs to migrate to each site. VMware vSAN Stretched Cluster Failover with Dual Site Mirroring You can take a look at my specific vSAN stretched cluster configuration in the referenced post on how to configure the solution. Sep 10, 2019 · Which vSphere license do I need to install a vSAN streched cluster? Is DRS necessary or is it possible to install a vSAN streched cluster without DRS using a standard or essential plus vSphere license? All three sites in a vSAN stretched cluster communicate across the management network and across the vSAN network. Verify that vCenter is operational. The VMs in all data sites communicate across a common virtual machine network. You protect your VMware Cloud Foundation environment against a failure of a single hardware fault domain by implementing multiple availability zones. All three sites in a vSAN stretched cluster communicate across the management network and across the vSAN network. Verify the latency requirements: Two-node vSAN clusters must have less than 500 ms RTT. Configure the port properties on each host to add the vSAN service. When Virtual SAN is deployed in a stretched cluster across multiple sites using fault domains, there are certain networking requirements that must be adhered to. To ensure high performance and availability, vSAN clusters must meet certain bandwidth and network latency requirements. When a VM storage policy of PFTT of "Dual-Site Mirroring" and an SFTT of 1 is used by the workload VMs. It is used to decide the virtual machine objects availability in the Stretched vSAN Cluster & 2 Node vSAN Cluster. The key requirement is the actual latency numbers between sites. The following is a collection of … Continued Apr 17, 2025 · - In a vSAN cluster, vSphere HA agents communicate over the vSAN network by default. Jul 7, 2025 · The VMware vSAN witness appliance is a specialized VMware ESXi installation that provides quorum and tiebreaker services for stretched clusters in VMware Cloud Foundation. VxRail 7. vSAN stretched clusters are typically deployed in environments where the distance between data centers is limited, such as metropolitan or campus environments. vxrail-appliance-series | Dell VxRail Architecture Overview | revision-history You can stretch a vSAN cluster in a workload domain across two availability zones within a region. If one site is down due to maintenance or failure and the witness host fails, objects become non-compliant but remain accessible. Mar 4, 2024 · With the release of vSAN 7 Update 3, administrators can even provision storage to traditional, non virtualized hosts via highly available NFS shares and iSCSI devices. 2 (the newest version), VMware added deduplication and compression as well as erasure coding; these processes add the ability to construct RAID 5/6 clusters. See vSAN Stretched HCI Cluster Storage Model for design requirements and recommendations. For the Management Domain on the default cluster of a VMware Cloud Foundation environment, the minimum requirements are as follows: Single Availability Zone (Standard vSAN cluster): 4 x ESXi hosts Two Availability Zones (Stretched vSAN cluster): 8 x ESXi hosts (4 on each site. This, in turn, avoids conflicts when vSphere HA and vSAN experience different partitions when failures occur. A VMware vSAN stretched cluster is a cluster configuration where the hosts that comprise a vSAN cluster reside in two geographic locations. May 30, 2017 · So if the requirement is PFTT=1 and SFTT=1 with the Failure Tolerance Method (FTM) set to RAID-5 then the vSAN Stretched Clustering configuration will be: 4+4+1. Dec 28, 2022 · Creating a vSAN Stretched Cluster with vSAN 8 explains in a practical way how to create a Cluster using the new vSAN architecture called ESA. See "Requirements for Enabling vSAN" in vSAN Planning and Deployment . The hosts that are listed under the Preferred fault domain are in the preferred site. The specific focus of the document includes overviews of: Sep 18, 2023 · vSAN stretched cluster -> Requires minimum 2 ESXi hosts in a vSphere cluster (one per site) and a witness host in the third site (the best option). For information about the considerations for a May 7, 2024 · Before we dive in about the list of Stretched Cluster Storage Policy lets us understand what defines a stretched cluster. The vSAN witness continuously monitors all hosts within the cluster to serve as a quorum in case of split-brain scenarios, and is fully managed by Microsoft. This requires an AWS VPC with two subnets, one subnet per availability zone. The appliance is a preconfigured virtual machine that runs ESX and is distributed as an OVA file. Configure the DCBx mode to IEEE. The witness host must be managed by the same vCenter Server managing the vSAN Cluster. Verify that your environment meets all requirements. The options below provide some of the different for stretched cluster network configuration. The third site, or tertiary site hosts a vSAN Witness Host that is connected Dec 24, 2024 · A private cloud created with a vSAN stretched cluster is designed to offer a 99. Select the hosts that you want to assign to the secondary fault domain and click >> . 0 Update 2 enables you to operate DRS in automatic mode, and recover gracefully from network partitions. A two host vSAN cluster consists of two data hosts and an external witness host. An enterprise license is required for encryption and stretched clusters. on a vSAN stretched cluster, you can use a default vSAN storage policy or create a storage policy compliant with the requirements of the vSAN stretched cluster. Note, that also when you use RAID-1 you will need at minimum 3 hosts per site. To disable UNMAP at the VM level, the following lists additional requirements are needed for it to function as intended. 0, you can now provide a fully site aware stretched cluster arrangement using vSphere clusters and vSAN storage clusters. Click Configure Stretched Cluster to open the vSAN stretched cluster configuration wizard. For information about assigning licenses, see assign-a-license-key-to-a-virtual-san-cluster. Simply declare via policy how vSAN should protect a VM and or VMDK, and vSAN will make it so. Navigate to the vSAN cluster. scsiUnmapAllowed flag with a value of 'false Verify that the data site to witness traffic connection has a minimum bandwidth of 2 Mbps for every 1,000 vSAN components. ) Feb 26, 2025 · If the test returns a warning or error, it means that the site latency exceeds the threshold of 5msec RTT between sites for a stretched cluster. DRS must be enabled on the cluster. You can choose the storage architecture and deployment option when creating a vSAN cluster. This can include anything from vSAN’s data placement schemes to stretched cluster topologies that maintain the availability requirements for customers. We will examine the different options when it comes to the Witness node, should it be . How can I size a vSAN cluster so that it meets my capacity and performance requirements? Stretched clusters extend the vSAN cluster from a single data site to two sites for a faster level of availability and intersite load balancing. Oct 3, 2024 · Learn how to stretch a VCF cluster with this detailed guide. Jul 16, 2025 · Explore VMware vSAN 9's biggest enhancements, including global deduplication, file services upgrades, Live Recovery, and improved stretched cluster features. Jul 3, 2025 · Overview of networking requirements for a witness appliance (VM) in a VxRail stretched or two node cluster. 0 is GA! Running vSphere Supervisor on vSAN Stretched Cluster provides instructions and best practices for deploying a Supervisor on a vSAN stretched cluster and configuring high availability (HA) for workloads running on TKG clusters. Configure the storage policy Site disaster tolerance rule to Site mirroring - stretched cluster. 99% infrastructure availability commitment when the following conditions exist: A minimum of six nodes are deployed in the cluster (3 in each availability zone). Today, I will discuss the hardware requirements for VMware's hyper-converged infrastructure solution. See “vSAN Cluster Design – Large Clusters versus Small Clusters” for more information. Stretching vSAN Clusters in VMware Cloud Foundation Monitoring Capabilities in the VMware Cloud Foundation System Updating VMware Cloud Foundation DNS and NTP Servers Supportability and Serviceability (SoS) Utility Replacing Host Components in VMware Cloud Foundation Managing Users and Groups in VMware Cloud Foundation Jan 14, 2025 · This service covers an Omnissa Horizon 8 deployment that builds on the replication capability of VMware vSAN and the high-availability (HA) features of VMware vSphere High Availability when used in a stretched cluster configuration between two data centers. 1 is the Stretched Cluster feature, with this feature Virtual SAN is enabling customers to have a 2nd site where the data exists in order to provide an increase in Availability and Data Protection, so what does the stretched cluster feature offer exactly?? Let’s take a look: Increased Enterprise availability and data protection Verify that the network infrastructure and the networking configuration on the ESXi hosts meet the minimum networking requirements for vSAN . In stretched cluster configurations, two data fault domains have one or more hosts, and the third fault domain contains a virtual witness appliance to help determine availability of the data sites. To do this, navigate to the Developer Center, then to API Explorer, and select Clusters. Create a cluster and add hosts to the cluster before enabling and configuring vSAN . Stretched clusters with less than 11 hosts per site must have less than 200 ms RTT. The A stretched cluster is configured by deploying an AVS private cloud across two availability zones (AZs) within the same region and placing a vSAN witness in a third AZ in that same region. vSphere Cluster Design Considerations You consider different number of hosts per cluster according to the storage type and specific resource requirements for standard and stretched vSAN clusters. The subnets determine an ESXi host placement between the two availability zones. When you deploy the vSAN witness appliance, you must configure the size of the witness supported by the vSAN stretched cluster. Use only the same model network adapters from the same vendor on each end of the connection. May 14, 2020 · You need to wait and upon successful boot of witness appliance, you can add it to respective in designated vSAN environment. The specific combination of policy To ensure high performance and availability, vSAN clusters must meet certain bandwidth and network latency requirements. stretched clusters can tolerate a witness host failure when one site is unavailable. Jul 7, 2025 · If the necessary latency, host shape, and network connectivity requirements are met, it can also be replicated in OCI Public Regions. Apr 1, 2025 · Please note that vSAN witness traffic and Data traffic should be configured on different VMkernel Port when mixed mode of MTU is used. Aug 12, 2019 · Primary role of vSAN Witness host is to be a witness in 2 Node vSAN cluster & vSAN Stretched Cluster configuration to avoid split brain scenarios. Learn about VMware vSAN. Sep 4, 2020 · These requirements may be hard to swallow for many organizations who simply are limited by the pipe between sites for doing vSAN stretched clustering. If you want to build a vSAN Stretched Cluster, you can also continue reading my other post about Configure vSAN Stretched Cluester. All VMs in vSAN ESA clusters are set by default to use UNMAP inherited from the cluster level. Compliance with the Additional Requirements vSAN stretched clusters extend the vSAN cluster from a single data site to two sites for a better level of availability and intersite load balancing. In v6. May 13, 2025 · Unable to configure vSAN cluster . This because locally you will have 2 “data” components and 1 witness component. In an environment with multiple availability zones, Layer 2 networks must be stretched between the availability zones by the physical infrastructure. The VSAN Stretched Cluster is setup across two sites, with preferably an identical number of ESXi hosts distributed evenly between the two sites, and a witness host residing at a third site. VMware Cloud Foundation vSphere cluster design must consider the requirements for standard, stretched and remote clusters and for the life cycle management of the ESXi hosts in the clusters according to the characteristics of the workloads. The subscription gets enabled to deploy a stretched cluster SDDC through the Azure portal. When using two availability zones, connect the vSAN witness appliance to the workload domain vCenter Server so that you can perform the initial setup of the stretched cluster and have workloads failover between the zones. With stretched-cluster, two-node, and ROBO (remote office/back office) deployment options, utilizing All-Flash or Hybrid modes, vSAN is proving to be incredibly flexible. Mar 13, 2023 · The VMware Stretched Cluster, aka the VMware Stretched Metro Cluster (vMSC) A stretched cluster is a deployment model in which two or more host servers are part of the same logical cluster but in separate geographical locations, usually two sites. Verify that the network infrastructure and the networking configuration on the ESXi hosts meet the minimum networking requirements for vSAN . Instead of using a dedicated physical ESXi host as a witness host, you can deploy the vSAN witness appliance. Consider the requirements for using vSAN storage for standard and stretched clusters in VMware Cloud Foundation , such as required capacity, number of hosts, storage policies, and the similar best practices for having vSAN operate in an optimal way. If activated, vSAN aggregates the specified local storage disks available on the hosts into a single datastore shared by all hosts. Select a witness host that is license to the cluster, or a license that covers advanced functions. vSAN activates the rapid provisioning of storage within VMware vCenterTM as part of virtual machine creation and deployment operations. You also must provide a Layer 3 gateway that is highly available between availability zones. Jun 19, 2025 · See the “ Design and Operational Guidance for vSAN Storage Clusters ” for more recommendations on the use of vSAN storage clusters. For vSAN stretched clusters, support is based on network latency and bandwidth requirements, rather than distance. Choose one of the following options: Jan 28, 2022 · vSAN Stretched cluster introduced in vSAN 6. Advanced features include RAID 5/6 erasure coding, and deduplication and compression. To protect against split-brain scenarios and help measure site health a When Virtual SAN is deployed in a stretched cluster across multiple sites using fault domains, there are certain networking requirements that must be adhered to. A standard vSAN cluster must contain a minimum of three hosts that contribute capacity to the cluster. Jan 1, 2023 · The vSAN Express Storage Architecture (ESA) introduced in vSAN 8 and enhanced in vSAN 8 through U3 delivers new capabilities that are unachievable in the vSAN Original Storage Architecture (OSA). You can use vSAN as the shared storage for a vSphere HA cluster. Pinging the Witness node from a vSAN ESXi host fails. Create two host groups, one for the preferred site and one for the secondary site. Click Next . From JSON configuration to NSX and vSAN setup, find everything you need to know The Stretched Cluster Model allows you to protect workloads on vSphere clusters in your environment against a failure of a single fault domain by implementing a stretched cluster across multiple availability zones. For more information about working with vSAN stretched clusters, see the vSAN Mar 13, 2025 · A short article on how to build a stretched vSAN cluster in the VCF. Please note that the final Standard vSAN Cluster needs to consist of a minimum of 3 vSAN Hosts (= no Witness) contributing Storage to vSAN to be fully operational Design Reference . Select a witness host that is For example, the implementation of a new network infrastructure or the migration of vSAN standard cluster (non-routed network) to a vSAN stretched cluster (routed network). As you have already heard, one of the major features in VSAN 6. When failures occur, vSAN uses a voting mechanism to determine object availability based on component distribution across sites and the witness host. This is due to missing networking requirements. vSAN Original Storage Architecture™ (OSA) environments are covered where they differ from vSAN ESA. This guide was developed to provide additional insight and information for the design, installation and configuration of vSAN stretched clusters. May 31, 2018 · Stretched Clusters for VMware Cloud on AWS enable customers to focus exclusively on requirements. The VMs in both data sites communicate across a common virtual machine network. Virtual SAN Stretched Cluster configurations can be spread across distances, provided bandwidth and latency requirements are met. vSAN aggregates locally attached disks of hosts that are members of a vSphere cluster to create a distributed shared storage solution. Stretched clusters with 11 or more hosts per site must have less than 100 ms RTT. Both availability zones must contain an equal number of hosts to ensure failover in case any of the availability zones goes down. UNMAP can be disabled using the disk. You deploy the vSAN witness host using an appliance instead of using a dedicated physical ESXi host as a witness host. The hosts within the private cloud are evenly Specific vSAN configurations, such as a stretched cluster, require a witness host. Click the Configure tab. See the Networking and Latency Requirements for vSAN Stretched Clusters and configure your network so that it meets the recommended requirements. Dec 10, 2024 · Update cluster by Stretching a standard vSAN cluster After a successful validation of the JSON specification, you are ready to update the cluster for stretching. In this video we will discuss what a VMware vSAN Stretched cluster is and the components that make one up. The network must be lossless. Introduction VMware vSAN is a hyperconverged, software-defined storage system integrated directly into the hypervisor. Verify that your environment meets the requirements listed in the Prerequisite Checklist sheet in the Planning and Preparation As per the vSAN Stretched Cluster Guide, several different network topologies are supported for vSAN Stretched Cluster. Configure This document primarily details the overall architecture and setup of vSAN Express Storage Architecture™ (ESA) cluster environments. vSAN Planning and Deployment describes how to design and deploy a vSAN cluster in a vSphere environment. In this document each data fault domain Jul 16, 2023 · In this blog post, I will explore the vSAN 8 requirements, focusing on different types of deployments and their respective considerations. A stretched cluster with fewer hosts that has been optimized with hardware and settings for performance may be an alternative to a single larger cluster that is trying to cover a wider variety of requirements. Specific vSAN configurations, such as a stretched cluster, require a witness host. This is so that in the event of a network failure, vSphere HA and vSAN are on the same network. Aug 16, 2016 · In my previous post, I introduced you to VMware VSAN . Sep 24, 2019 · A vSAN stretched cluster must meet certain basic networking requirements: Management network requires connectivity across all three sites, using a Layer 2 stretched network or a Layer 3 network. In other words, the Underlying Network between the vSAN ESXI data hosts and the witness appliance host do not meet the requirements. All hosts must support RDMA. The data sites are connected via a high bandwidth/low latency link. vSAN 7. Dec 21, 2022 · Network Requirements for the ESA in Stretched Clusters While the vSAN ESA has new networking requirements connectivity of hosts in a standard vSAN cluster, the network requirements for the ISL in a stretched cluster remain the same. If any host loses RDMA support, the entire vSAN cluster switches to TCP. The two sites typically have an equal number of hosts residing in each site, and are connected using a high bandwidth/low latency connection known as an inter-site link, or ISL. 1 introduced VMware VSAN Stretched Cluster configuration. In my opinion, this is one of the primary advantages of the VMware Cloud on AWS Service. Dec 4, 2024 · Deploy a stretched cluster private cloud When the request support details are received, quota is reserved for a stretched cluster environment in the region requested. The method for stretching these Layer 2 networks and providing a highly available Layer 3 gateway is vendor-specific. Sep 1, 2016 · VSAN v6. 1 and it brings high availability in an active-active fashion. The appliance is a preconfigured virtual machine that runs ESXi and is distributed as an OVA file. dita#GUID-A2A2EDDA-4C4D-438C-98DF-6511C5DF72B2-en. Aug 28, 2025 · The vSAN Witness node cannot form a cluster with the remaining vSAN data nodes in a stretched cluster configuration. Oct 16, 2025 · Convert a 2-Node Stretched Cluster to a Standard vSAN Cluster by adding additional Host (s) Optional: Remove vSAN Hosts while converting to a Standard vSAN Cluster. Configure DRS settings for the stretched cluster. The third site Jan 31, 2020 · This article will help you to understand the detailed step by step procedure to create a vSAN Stretched cluster using vSAN witness node Specific vSAN configurations, such as a stretched cluster, require a witness host. Summary With the very latest updates to vSAN in VCF 9. Aug 17, 2022 · A vSAN stretched cluster is a special type of vSAN cluster configuration where organizations want to build out their vSAN cluster for resiliency and downtime avoidance purposes. vSAN vSAN storage clusters are powered by the ESA, which provides tremendous flexibility in meeting performance, capacity, and resilience requirements for all types of environments. vSAN deployments require specific network ports and settings to provide access and services. May 20, 2025 · Configure VMware vSAN ESANote vSAN TRIM/UNMAP is enabled by default on vSAN ESA based clusters. All three sites in a stretched cluster communicate across the management network and across the vSAN network. dcff fppcs fjwa uysik dkyczp cni pccwub nalncew cnknd ptrgp wkkauvo hzgta pbyw gpol ygnamb