All hosts have a vsan vmknic configured witness. Deploy the appliance to a vSAN host or cluster.
All hosts have a vsan vmknic configured witness vSAN Planning and Deployment describes how to design and deploy a vSAN cluster in a vSphere environment. In the event of a partial failure of the fabric, all vSAN communications are redirected to the healthy fabric on the affected hosts. 7. Feb 28, 2025 · The warning "Host is in a vSAN cluster but does not have vSAN service enabled" typically gets triggered during the configuration of vSAN when the cluster in vCenter has been configured for vSAN but the hosts are mid process of being configured but the warning should clear once the task completes. This ensures that the hosts are active and indicates the participation of hosts in the vSAN Jul 31, 2025 · Prior to vSAN version 8. Unicast transmits the heartbeat sent from the primary host to all other hosts each second. This KB takes you through the process step-by-step and assumes the original (old VLAN/subnet) VMK interface will be deleted. If ESXi host firewall has blocked port 443 port (ruleset vSphereClient) for vSAN network. Dec 20, 2018 · Conforming to the vSAN Network Requirements, a dedicated vSAN network has been created. 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. Is that all or am I missing something? 18 hours ago · This test checks whether all the hosts in the vSAN cluster have a vmknic configured for vSAN traffic. 0 U2 the vSAN master host retrieves remote host stats via port 80 and from vSAN 8. Next best steps are: Set a static ip address and subnet for all hosts vmkernel ports that is on the same L2 network. I am running 2 ESXi 7. Verify that you have identical VLAN, MTU and subnet across all interfaces. Its only purpose is to serve as a vSAN witness. Pinging the Witness node from a vSAN ESXi host fails. The 'Network' group of vSAN health-checks checks the following: 'All hosts have a vSAN vmknic configured' 'Hosts disconnected from VC' 'Hosts with LACP issues' 'Hosts with connectivity issues' 'Hosts with duplicate IP addresses' 'vSAN cluster partition' 'vSAN: MTU check (ping 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. After all hosts are configured, configure your vSAN Cluster. May 27, 2025 · Further information on vSAN networking may be found with the vSAN Network Design Guide. The hosts I am using are SuperMicro SYS E200-8D. Run the command " esxcfg-vmknic -l " to verify the MTU set on the VMkernel adapter (vmk) Specific vSAN configurations, such as a stretched cluster, require a witness host. ESXCLI Commandsesxcli vsan Commands Virtual SAN Command Line Commands There are many CLI commands available to manipulate VMware Virtual SAN—both to configure it and to get status information about it. Due to this partial failure, a subset of the hosts in the cluster are unable to communicate with each other. All commands are from the latest vSAN 6. Rebuild the vSAN Unicast Agent List Use the esxcli command to configure the Unicast agent The most obvious one is "all host have a VMKNIC configured", but I did assign a VMKernal adapter to the same internal switch, and check the checkmark for VSAN. From the Host UI the vSAN datastore doesn't show it's total expected size, just the size of the total disks associated with the host or the total size of all hosts that can communicate with each other Mar 29, 2023 · Veeam MP for VMware Reference > Rules and Monitors > Event Monitors > Veeam VMware Virtual SAN Alarms Veeam VMware Virtual SAN Alarms Page updated 3/29/2023 Send feedback Jul 25, 2017 · The "vSAN 6. In this test, all nodes ping all other nodes in the cluster. If this passes, basic unicast connectivity is vSAN traffic. 0 U2 and later builds, port 443 is used. Verify that you can run vmkping successfully between all hosts. These warnings should be resolved after the new VMkernel adapters for vSAN have been added and configured correctly on all hosts in the cluster. Two-node Mar 20, 2018 · Been wrestling with this for weeks now. However, I wanted to up the performance of the vSAN network so revisited the options available to architect the vSAN network. Jul 9, 2019 · | All hosts have a vSAN vmknic configured | vsanvmknic | Normal | Jan 15, 2025 · Partial failure of the fabric occurs when some, but not all, of the network links of a fabric are down. New hosts are configured based on projected workloads (plus points for utilising vSAN Ready Nodes), they’re purchased, racked,… Continue reading → Deploying vSAN with vCenter Server Appliance Feb 18, 2025 · Make sure you have all the ESXi hosts from the vSAN cluster added to the vCenter cluster. This witness appliance will host witness components that are being used in split-brain failure scenarios. The vSAN creates a network partition on the host due to delayed network connectivity and isolated that host. Let’s quickly look at helpful information to help VI Administrators diagnose potential problems. Re-enable the stretched cluster and follow the Wizard and have it create new disks to house the witness components. !The following!example!will!demonstrate!how!to!configure!a!Virtual!SAN!network!on!an! Jul 15, 2019 · I have all my ESXi which have vsan enabled on vmk1 (192. RVC is an interactive command line tool to control and automate your platform. Unicast traffic is a one-to-one transmission of IP packets from one point in the network to another point. Symptoms: Direct connect 2-node vSAN cluster Although all the hosts can ping the witness appliance and both hosts have correct unicast table entries, the witness will not join the cluster. Checks if all of the hosts in a vSAN cluster have consistent non-default advanced configuration options. Sep 27, 2021 · But, I can see that the ESXi hosts' witness traffic is tagged at vmk0 as the management kernel port; my understanding it is recommended. The appliance is a preconfigured virtual machine that runs ESXi and is distributed as an OVA file. Additional health service checks on the network are designed to assist you on finding the root cause of what may be causing the network partition. 5) is configured with 2 node direct connection with witness appliance. For the rest of the cluster, the physical hosts have the vSAN Witness tagged on their management interfaces. The document provides an overview of the networking requirements and best practices for VMware's Virtual SAN (vSAN). We need to configure the networking for the Witness host via DCUI which is very familiar for all of us. My questions might seem basic to most of you, please bear with me. You can verify that the vmknic used for the vSAN network is uniformly configured correctly across all hosts, check that multicast is functional, and verify that hosts participating in the vSAN The 'vs_network' check test collects the result of the vSAN Health-check from vCenter (VC), for the Network category. After a power outage and power is restored, vSAN datastore is showing inaccessible, and VMs may appear to be in an invalid state. The switch is configured with VLT on a 1g port. #esxcli vsan network list Interface VmkNic Name: vmk1 Nov 6, 2025 · esxcli vsan storagepool remove -u <VSAN Device UUID> or esxcli vsan storagepool remove -d <VSAN Device ID> 4. GitHub Gist: instantly share code, notes, and snippets. Resolution Q: What does the Network Health - All hosts have a vSAN vmknic configured check do? To participate in a vSAN cluster, and form a single partition of fully connected ESXi hosts, each ESXi host in a vSAN cluster must have a vmknic (VMkernel NIC or VMkernel adapter) configured for vSAN traffic. 5 Disable HA before enabling vSAN Create vSAN vmkernel ports prior to enabling vSAN Enable vSAN service on vSAN vmkernel NIC assigned to vSAN vswitch (ideally vDS) (license - vDS included with vSAN) Minimum # of host for vSAN is 3 You will need a virtual Witness Appliance to do 1+1 Verify that redundant NIC teaming connections are configured. After adding the Witness Host to vCenter, you have to edit the VMkernel adapter for the witnessPG Select the (blue) Witness Host and go to Configure > Networking > VMkernel adapters. All hosts must support RDMA. Sep 15, 2019 · Reading Time: 11 minutesvSAN deployments in brownfield environments are simple. Just wanted to know whether the issue is with the VLT and wanted to know how to check the interface Verify that the network infrastructure and the networking configuration on the ESXi hosts meet the minimum networking requirements for vSAN . Compounding the problem is that the VMs that will run on the host also have a vlan assigned to that same network port Feb 26, 2025 · In the automated shutdown logic, a specific host is chosen as the orchestration host. If you are new to RVC, make sure to read the Getting Started with Ruby vSphere Console Guide. vSAN stretched clusters with less than 11 hosts per site must have less than 200 ms RTT. Up until now, I have simply had (2) 10 gig connections in active and standby for basically failover purposes only. Configure the DCBx mode to IEEE. Aug 22, 2025 · Repeat Steps 3 to 10 for each host that is a member of the vSAN cluster. The purpose of this host is to orchestrate the entire shutdown process automatically across the cluster and it will change necessary advanced settings, enter the hosts in maintenance mode and shut them down accordingly. Click " Retest " to rerun the vSAN Healthcheck to evaluate if the " Host compliance check for hyperconverged Cluster configuration " has now turned to green (= resolved). The network must be lossless. Hosts with connectivity issues May 5, 2022 · For the rest of the cluster, the physical hosts have the vSAN Witness tagged on their management interfaces. This setup is ideal for small to medium-sized businesses or remote office/branch office (ROBO) environments that may have limited resources but still require the benefits of vSAN. Stretched clusters with 11 or more hosts per site must have less than 100 ms RTT. They are all configured to use vmnic 0 with 2020 as the management vlan. This should re-form the cluster successfully and allow the witness components to re-build on the newly created virtual disks. Apr 14, 2019 · Disable vSAN Health Alarm 10 minute read Introduction I am currently rebuilding my lab as it was time to refresh it. 168. vSAN has a distributed architecture that relies on a high-performing, scalable, and resilient network. The advanced configuration with default value will be skipped and not shown in the result. Unlike a general purpose ESXi host, the witness appliance does not run virtual machines. Aug 12, 2025 · This article provides commands for performing a basic health check of Virtual Storage Area Network (VSAN). Check your MTU settings as well, I would enable the health check if you are using vDS. 0. Feb 4, 2021 · | All hosts have a vSAN vmknic configured | vsanvmknic | Normal | | All hosts have matching multicast settings | multicastsettings | Normal | May 14, 2020 · As part of vSAN Stretched or 2-Node cluster configuration, a witness appliance should be deployed and configured. This is useful when vCenter is offline or when using Secure Remote Services for enhanced troubleshooting. Two-node vSAN Feb 17, 2020 · * All hosts have a VSAN vmknic configured Physical disk * Physical disk health retrieval issues Data * vSAN object health Cluster * ESXi vSAN Health service installation * vSAN Health Service up-to-date * vSAN CLOMD liveness * vSAN cluster configuration consistency * Software version compatibility * Disk format version vSAN iSCI target service The 'vs_network' check test collects the result of the vSAN Health-check from vCenter (VC), for the Network category. | All hosts have a vSAN vmknic configured | vsanvmknic | Normal | | All hosts have matching multicast settings | multicastsettings | Normal | Load balancing set to Route based on originating port ID Network failure detection set to Link Status Only Notify Switches set to the default value of Yes Failback set to the default value of Yes The uplink configuration has one uplink in the Active position and one uplink in the Unused position. 本文提供用于执行虚拟存储区域网络 （VSAN） 基本运行状况检查的命令。它还可以帮助对 ESXi 主机 SSH 会话中的对象级问题进行故障处理。当 vCenter 处于离线状态或使用 Secure Remote Services 增强故障处理时，此功能非常有用。 Sep 26, 2025 · Several vSAN Components of the same vSAN Object (= VM data) may be flagged as "Stale" as a result of placing multiple vSAN hosts in "No Action/No data evacuation" Maintenance Mode, followed by simultaneously rebooting multiple vSAN hosts. All!ESXi!hosts!in!a!VSAN!cluster!communicate!over!a!Virtual!SAN!network. Configure the vSAN network on the witness appliance. 6 and later releases support unicast communication. Deploy the appliance to a vSAN host or cluster. But in order to get to the workload management piece, I need to get my lab to have a functional vSAN cluster. For more information on the unicast communication, see Using Unicast in vSAN Network. It categorizes object health to help you assess not only if an object is healthy or unhealthy, but whether an administrator should take action or whether an environment is For any host with multiple vSAN Max Client vmknics configured, please navigate to Host > Configure > Networking > VMkernel Adapters, and unselect unnecessary VMKernel adapters to only keep one vSAN Max Client vmknic for the host. For more information on Layer 2 and Layer 3 network topologies, see Standard Deployments. Sounds like you have done this. Aug 27, 2018 · Hello ChrisFD2 , Just to clarify - are you trying to set-up WTS (Witness traffic Seperation)? This needs to be configured via the CLI with the data-nodes set for type witness traffic on the alternate interface and the Witness set as vsan traffic: Configure Network Interface for Witness Traffic More info: Understanding the vSAN Witness Host - Traffic Tagging - Virtual Blocks https://storagehub May 10, 2025 · This health check is similar to another check that looks for unexpected vSAN cluster members. Hosts disconnected from VC This check verifies that the vCenter has an active connection to all ESX hosts in the vSAN cluster. All host nodes within a vSAN cluster communicate over the IP network. It provides a cluster wide overview by summarizing all objects in the cluster. 1. Two-host vSAN clusters must have less than 500 ms RTT. Configure the management network on the witness appliance. Make sure to VMware vSAN uses a software-defined approach that creates shared storage for virtual machines. Jun 14, 2017 · hi there, In our test environment, vsan (version 6. Add the appliance to vCenter Server as a witness ESXi host. See Lockdown Mode on how to configure Lockdown mode (select installed Build): This Issue happens on all servers at an vSAN cluster while one or more nodes are down for maintenance mode, and therefore they are not able to communicate with each other. Check below: vCenter needs to be at 6. I read the KB and it looks like 6. 7u3 with all the updates. Jun 15, 2019 · Hi All hosts will need to have a VMkernel port configured that has the vSAN Service Enabled. I have a vSAN 6. Oct 28, 2025 · In the above example, the vSAN VMkernel adapter (vmk1) is associated with the specified vSphere Distributed Switch (vDS). For more information, see Enabling or disabling a vSAN cluster. The witness component will act as a tie-breaker and help vSAN cluster to satisfy the quorum requirements. Especially for home labs, where unsupported hardware is ESX hosts in a vSAN cluster have been configured so that all vSAN VMkernel NICs are on the same IP subnet. Verify the current cluster configuration to ensure all active and valid nodes are accounted for. Mar 22, 2022 · What happens when you use vmkping -I <vsan vmknic> <peer address> from one host to another? Note, that is a capital i, not a lowercase L. Sep 24, 2025 · The network configuration issue needs to be located and resolved. Therefore, it is confirmed that vmnic1 and vmnic0 are being used for vSAN communication and the vSwitch is configured with an MTU of 9000. The 'Network' group of vSAN health-checks checks the following: 'All hosts have a vSAN vmknic configured' 'Hosts disconnected from VC' 'Hosts with LACP issues' 'Hosts with connectivity issues' 'Hosts with duplicate IP addresses' 'vSAN cluster partition' 'vSAN: MTU check (ping Apr 24, 2020 · Hello y'all! I am taking my first steps with workload management capabilities. 0 support only Layer 2 networking, whereas subsequent releases include support for both Layer 2 and Layer 3 protocols. In the fourth part, I'm working with commands Verify that the data site to witness traffic connection has a minimum bandwidth of 2 Mbps for every 1,000 vSAN components. Fortunately, this is mostly mitigated by the VMware Cloud on AWS service. This health check validates the presence of the default vmknic for the vSAN iSCSI target service, and verifies that all the existing targets have valid vmknic configurations. This article provides commands for performing a basic health check of Virtual Storage Area Network (VSAN). Additionally, it emphasizes the need for adherence to best practices to ensure a successful Feb 14, 2017 · Hard to say without a complete picture of the environment. 0 had a patch for this alarm but we are 6. Pinging an ESXi host from a Witness works, but not with a full TCP frame. It also has two network adapters, one for the management network and another for the vSAN network to carry vSAN traffic. The two platforms on which these CLI commands can be used are RVC on the Vcenter server and ESXCLI on the ESXi host. Use ESXCLI and RVC commands to verify that the network is fully functional, and to troubleshoot any network issues with vSAN . Hosts with connectivity issues (hostconnectivity) green vSAN cluster partition (clusterpartition) green All hosts have a vSAN vmknic configured (vsanvmknic) green vSAN: Basic (unicast) connectivity check (smallping) green Mar 26, 2018 · Click on the Warning Message o – All hosts have a vMotion vmknic configured You Can see there 3 nodes on the vSAN cluster and there is not vmotion configured on all three Apr 8, 2025 · vSAN Stretched cluster - Shared witness cluster number of data hosts exceed (7. Each vSAN host must have a vSAN certified RDMA-capable NIC, as listed in the vSAN section of the VMware Compatibility Guide. The alert may trigger with mis-configured MTU settings in the vSAN network in the datacenter. x. vSAN stretched clusters with 11 or more hosts per site must have less than 100 ms RTT. 0 U2 and higher) Sep 17, 2018 · When deploying the vSAN Witness Appliance, there are 3 potential deployment options: Tiny, Normal, & Large. The information includes system requirements, sizing guidelines, and suggested best practices. As a result, separate interfaces need to be tagged as witness traffic. Hosts with connectivity issues This check refers to situations where vCenter lists the host as connected, but I went through and verified vm kernel adapters and that vSAN was enabled on all four hosts, I verified the IP addresses were pingable, that the uplinks were good. Each vSAN node has been assigned six NICs (two per service), all of which have been configured as uplinks within the appropriate Virtual Distributed Switches. The vSAN Witness node cannot form a cluster with the remaining vSAN data nodes in a stretched cluster configuration. The same will be true when the witness needs to reach the data sites. The vSAN health might report an incorrect status for the network health check of the type "All hosts have a Virtual SAN vmknic configured" and then trigger the false vCenter Server alarmThe vSAN health may also report "Physical disk health retrieval issue" under Physical Disk Health though there are no disks which are in 5 days ago · The blog outlines deploying the vSphere Supervisor on a vSAN Stretched Cluster, essential for maintaining high availability and disaster recovery of Kubernetes workloads. Jan 19, 2019 · I have a third host arriving soon so I thought I would take the opportunity to cover a 2 node setup before I migrate. 1. I will cover the homelab equipment in more detail in another post, today is just the installation of the two hosts, vCenter, network configuration, vSAN witness appliance & setup. Use the "Retest" button in vSAN Skyline Health to refresh the health checks status. Apr 9, 2025 · Q: What does the Network Health - All hosts have a vSAN vmknic configured check do? To participate in a vSAN cluster, and form a single partition of fully connected ESXi hosts, each ESXi host in a vSAN cluster must have a vmknic (VMkernel NIC or VMkernel adapter) configured for vSAN traffic. Verify that VMkernel port for vSAN network traffic is configured on each host. You can configure basic Active/Active NIC Teaming with the Route based on Physical NIC Load policy for vSAN hosts. Sep 14, 2015 · Now when the ESXi hosts on the data sites need to reach the VSAN network on the witness host, it will not use the default gateway, but whatever path has been configured on the static route. Instead of using a dedicated physical ESXi host as a witness host, you can deploy the vSAN witness appliance. vSAN Data and Witness traffic shares the same vSAN vmknic, therefore, shares a single MTU setting. Stretched clusters with less than 11 hosts per site must have less than 200 ms RTT. The witness also acts as tie-breaker in scenarios where a network partition occurs between the two data sites. Silenced checks are displayed with a green checkmark and are marked as "Skipped". From going over the 2-Node Cluster Guide again, it would appear that to move this to a supported config all I need to do is move the vSAN tag from the Witness' vmk1 to vmk0 (Management). If both host1 and host2 are up and running (witness as well) then all the vms seems inaccessible (orphan) on the hosts Jun 13, 2023 · Hello, years ago I configured a vSAN stretched cluster, the witness was on a remote site so I used a dedicated witness interface with a dedicated route as descr Jul 3, 2025 · The witness appliance is expected to have 2 virtual standard switches (vss) named vSwitch0 and secondarySwitch with porgroups named Management Network and VM Network on vss vSwitch0 and secondaryPg on vss secondary switch. 6 is the ability to silence Health Checks. It's not a rocket science because all these steps are done when you stretc Oct 18, 2017 · 'All hosts have a Virtual SAN vmknic configured' - Are all hosts that are intended to be in the vSAN cluster in a vCenter cluster object with no other nodes under this object? This Alert is triggered when > 30 percent packet loss while pinging with small/large packets. 6 version. Use only the same model network adapters from the same vendor on each end of the connection. Aug 28, 2025 · Local Node State: Discovery Then the Witness is confirmed to be isolated from the vSAN Cluster. It discusses the importance of multicasting for vSAN operations, outlines specific networking configurations, and shared insights on troubleshooting and performance optimization. 0/24, vlan 2) Vlan 1 and vlan 2 are present on both sites, replication is wanted to be L2. This check ensures that all ESXi hosts in a vSAN cluster have vSAN enabled. xx. Management and vMotion services have also been assigned to a dedicated network segment. Usually the witness resides at the main site, along with the vCenter Server. While working on servers' firmware upgrade (most likely network isolation and plus cold reboot), I think I've caused split brain in our vsan cluster. Hosts with connectivity issues vSAN traffic. /sos --stretch-vsan' command is initiated. Configuring vSAN VMkernel networking on a distributed virtual switch To configure vSAN VMkernel networking on a distributed virtual switch: | All hosts have a vSAN vmknic configured | vsanvmknic | Normal | | All hosts have matching multicast settings | multicastsettings | Normal | May 8, 2018 · vSAN requires an VMkernel network adapter for the network communication between vSAN Cluster. vSAN: Basic (unicast) connectivity check This test performs a basic ping test with a smaller MTU value just to ensure the vSAN vmknic connectivity. Silencing health checks is one step further and enables you to have a clean vSAN health. 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. First deploy the VM from OVF, then clone the VM, and configure each clone as a witness host for a different cluster. May 21, 2025 · The Basic connectivity check for vSAN, also known as a unicast or small ping test, automates the pinging of each ESXi host from each of the other ESXi hosts in the vSAN cluster and ensures that connectivity between all the ESXi hosts on the vSAN network exists. Oct 29, 2024 · After adding the Witness Host to vCenter, you have to edit the VMkernel adapter for the witnessPG Select the (blue) Witness Host and go to Configure > Networking > VMkernel adapters. But if you move the witness host out of the cluster, the cluster remains in a misconfigured state. For more information on the unicast communication, see Chapter 4 Using Unicast in vSAN Network. 0 beta hosts nested on a physical ESXi 6. However, I do not see that configuration at the witness appliance; the witness appliance uses vmk1 for witness traffic, as shown in the listing below. Apr 9, 2025 · The vSAN network is isolated between the host vSAN nodes. If any host loses RDMA support, the entire vSAN cluster switches to TCP. 5 All hosts at 6. Next morning another Host had dropped from vCenter with other alarms triggering such as “vSAN health alarm 'All hosts have a vSAN vmknic configured'” vSAN health alarm 'Host issues retrieving hardware info' vSAN health alarm 'Time is not synchronized across hosts and VC along with vSAN daemon liveness EPD status being in a abnormal state. Verify the latency requirements: Two-node vSAN clusters must have less than 500 ms RTT. . ” Host Uplink Counts Per Host Teaming for performance and redundancy generally assumes the use of more than one physical NIC, where each NIC may have 2 to 4 NIC ports. Configure cluster that uses a third host as a witness, which can be located remotely from the branch office. 6. It details prerequisites, spanning dual active sites and necessary network configurations, and provides a comprehensive guide for deploying the Supervisor, ensuring resilient workload management across data centers. 5!specifically!for!Virtual!SAN. Oct 9, 2016 · Now Host 1 (HP) and Nested hosts tell me they cant communicate with all other nodes in the Virtual SAN enabled cluster. With vmk0 on the Management Network porgroup used for witness management, vmk1 on portgroup secondaryPg to be used for accepting witness traffic from vSAN hosts or otherwise vSAN Monitoring and Troubleshooting describes how to monitor and troubleshoot VMware vSAN ® by using the vSphere Client. This issue occurs because the MTU set on the vSAN Witness ESXi host/Appliance network does not match with the vSAN data node network in the vSAN cluster. Deploying the ESXi and VCSA OVAs is very easy in v15 so a single PC has more WAF than a bunch of server class machines. The docs say: "In the illustration below, each vSAN Host's vmk0 VMkernel interface is tagged with both "Management" and "witness" traffic. All the hosts must maintain IP unicast connectivity, so they can communicate over a Layer 2 or Layer 3 network. Symptoms: vSAN Skyline Health alert " Network Health - vSAN Cluster Partition " is triggered and shows the witness host in a separate partition: vSAN Skyline Health alert Once the VSAN network has been created, and VSAN is enabled, you should check that each ESXi host in the VSAN Cluster is able communicate to all other ESXi hosts in the cluster. Jul 14, 2025 · This article is for environments where vSAN Witness Traffic separation is configured on the vSAN data nodes via Witness traffic tag or modifying a vSAN Cluster after major network change resulting in a vSAN Cluster Partition. !This!is!a! new!VMkernel!port!type!introduced!in!vSphere!5. Apr 26, 2017 · A new feature in vSAN 6. The vSAN Network Design guide describes network requirements, network design, and configuration practices for deploying a highly available and scalable vSAN cluster. Hosts disconnected from VC This check verifies that the vCenter Server has an active connection to all ESXi hosts in the vSAN cluster. The witness host cannot be part of the vSAN stretched cluster, and it can have only one VMkernel adapter configured for vSAN data traffic. To do this we run the following command: esxcli vsan cluster new View and take note of the new vSAN Sub-Cluster UUID by running the following command: esxcli vsan cluster get Example with output: [root@se-emea-vsan01:~] esxcli vsan cluster get Oct 8, 2025 · Occasionally, it is necessary to change the IP scheme in use for parts or all of the environment. Jun 3, 2025 · During VCF bringup once the cluster is created the cluster Quickstart configuration is not completed. Will that allow it to be used as a Witness node? Seperatly, I am reading the docs and have confusion around "witness" trafic. The vSAN Witness Host has the vmk0 VMkernel Jan 12, 2020 · In this blog post i will describe what is going on in the background when '. 0/24, vlan 1) and vmk2 (192. The sixth part is about troubleshooting vSAN Aug 17, 2022 · The vSAN witness appliance is configured similarly to the vSAN ESXi host data nodes in the data sites. When I run the configuration check, everything shows green except for the "vSAN cluster partition error" as seen below: I see that the witness host is running on partition 1 and my two vsan hosts are running on partition 2. vSAN Cluster UUID is out of sync between vCenter and ESXi In very rare circumstances this warning Aug 12, 2019 · To separate data traffic from witness traffic, you can configure a dedicated VMkernel network adapter for vSAN witness traffic. This check ensures each ESXi host in the vSAN cluster has a vmknic configured for vSAN Once all the VMKernel interfaces are configured on all the hosts, create a vSAN Cluster on any one host. Networking requirements for vSAN Witness Appliance: Data site to witness traffic connection require a minimum bandwidth of 2 Mbps for every 1,000 vSAN components. Jul 21, 2023 · A 2-node vSAN cluster is a configuration where you can create a highly available and fault-tolerant storage infrastructure using just two physical hosts. As seen in the above logs, the IP changes from the vSAN-IP 19. In previous versions, it was already possible to disable alerts that are triggered by health checks. VMkernel Network Each ESXi host in a vSAN cluster must have a network adapter for vSAN Jun 20, 2023 · Hi, I have a 3 node vsan cluster connected to 2 dell s3124 switch. 2. I am quite new the VMware products and I probably made an error in setting this all up somewhere, although with this config it is as default as it can get. The reasons can range from mis-configured subnets (all ESXi hosts must have matching subnets), mis-configured vSAN traffic VMkernel adapters (all ESXi hosts must have a VSAN vmknic Aug 2, 2024 · In order to participate in a vSAN cluster, and form a single group of fully connected hosts, each host in a vSAN cluster must have a vmknic (VMkernel network interface or VMkernel adapter 5 days ago · Additional documents: Network partition caused by an invalid/incomplete unicast agent list on vSAN host (s) vSAN Health Service - Unicast agent not configured vSAN Health Service - Witness host not found The mechanism of vCenter updating/modifying the Unicast Agent lists on the Hosts can be disabled by running on all Hosts: Jun 18, 2025 · The vSAN health might report an incorrect status for the network health check of the type "All hosts have a Virtual SAN vmknic configured" and then trigger the false vCenter Server alarm The vSAN health may also report "Physical disk health retrieval issue" under Physical Disk Health though there are no disks which are in failed state in cmmds Feb 1, 2019 · Even if an ESXi host is part of the vSAN cluster, but is not contributing storage, it must still have a VMkernel NIC configured for vSAN traffic. There are different configuration options available. This process of failing over to a healthy link (on Jul 6, 2024 · In today’s blog post, I revisited the topic of vSAN and looked at the basics of the storage layer. Verify that flow control is enabled on the ESXi host NICs. Feb 4, 2021 · | All hosts have a vSAN vmknic configured | vsanvmknic | Normal | | All hosts have matching multicast settings | multicastsettings | Normal | Jul 22, 2021 · I have multiple esxi hosts. I am not a vSAN admin. Malfunctioning hardware like SFP, physical switch port, cables can also result packet loss. For more information, see Deploying OVF Templates in the vSphere Virtual Machine Administration documentation. 181 to the Witness-IP Apr 1, 2025 · Cause This is an expected behavior due to the mismatch in MTUs. After power cut, the network of the host are corrupted and partitioned. Any failures/connection issues as described above, might result vSAN objects unable to switch from "Absent Stale" state back to a healthy state and therefore 6. It can also help troubleshoot object-level issues from an ESXi host SSH session. Jun 26, 2019 · It is pre-configured and licensed. For VCF environments, see “ Network Design for vSAN for VMware Cloud Foundation. This is essential to participate in the vSAN cluster and for all the hosts to be in the same network partition group. All hosts have matching subnets This check tests that all ESXi hosts in a vSAN cluster have been configured so that all vSAN VMkernel NICs are on the same IP subnet. Feb 28, 2023 · Cheers. If you place the witness host in a vSAN-enabled vCenter cluster, an alarm notifies you that the witness host cannot reside in the cluster. 6 2-host cluster with external witness. Besides management, vmotion, and vsan vlans are configured on the port. Use a vSphere Distributed Switch (vDS). Apr 12, 2019 · vSAN Health Service tests categories. Oct 10, 2025 · Follow these steps to manually rebuild the Unicast Agent List on each host: 1. I used the vSAN > Virtual Objects will be blank or only report certain VMs vSAN > Resyncing Components will not report on syncing data vSAN > Health may be reporting multiple errors Network - Hosts with connectivity issues Network - All hosts have a vSAN vmknic configured Cluster - Advanced Configuration in Sync HostX reporting inconsistent configuration Download the appliance from the VMware website. 6 RVC Guide" series explains how to manage your VMware Virtual SAN environment with the Ruby vSphere Console. The problem is the way the network is configured the switch port all hosts connect to are trunk ports. For more information, see Creating a vSAN Stretched Cluster or Two-Node vSAN Cluster. As a result, the vSAN health reports a warning that hosts are still in Maintenance mode, as vSAN health expects all the hosts in Maintenance mode if the cluster is in Quick start configuration i. The host interfaces in the data sites communicate to the witness host over the vSAN network. Use a Layer 2 or Layer 3 network to provide communication between the data sites and the witness site. A "VMK" HA functionality feature was introduced in vSAN which allows 2 VMK interfaces to have vSAN enabled on them at the same time. It virtualizes the local physical storage resources of ESXi hosts and turns them into pools of Aug 9, 2025 · Q: What does the Data Health – vSAN Object Health check do? The object health checks are designed to provide two aspects at a very fast glance. If this fails, then you may need to re witness host resides at a third site to provide the witness function. Sep 16, 2025 · Steps for replacing the witness appliance/host for vSAN Stretch Clusters, 2-Node Stretch/Robo Clusters, 2-Node Stretch Direct Connect Clusters. You don’t need to provide a license for ESXi (vSAN witness appliance). e if the Quick start configuration is not completed. I run it all nested on VMware Workstation 15 as I have a powerful enough PC to run a nested three host cluster easily. 0 U1 and higher) vSAN Health Service - Stretched cluster - Witness node is managed by vLCM (8. It is on a distributed Feb 26, 2025 · To address this: Configure the Lockdown mode on vSAN Host to match with other vSAN Hosts. Configuration Assist identifies the issue configuration issue and includes the “Create VMkernel Network Adapter” button. Jul 28, 2017 · The "vSAN 6. In this post we will see on How to create vSAN VMkernel step by step or How to configure vSAN VMkernel step by step. The following figure shows a 3-node cluster where the hosts do not have a vSAN vmknic configured. Is this the cause of the failure? I cannot seem to troubleshoot this Resolution If warnings or failures are shown for any of the vSAN capacity utilization checks, see the following Dell or VMware knowledge base articles: All hosts have a vSAN vmknic configured vSAN Health Service - Network Health - All hosts have a vSAN vmknic configured (2108062) Hosts disconnected from VC vSAN Health Service - Network Health - Hosts disconnected from vCenter Server (2108004 Specific vSAN configurations, such as a stretched cluster, require a witness host. These deployment profiles all have 2 vCPUs, 1 vmdk for the ESXi installation, 1 vmdk for the vSAN cache device, and at least 1 vmdk for the vSAN capacity. check the VLAN ID on the virtual Switch and ensure the VLAN is set the same Check the physical switches to ensure the connections into these are all Verify that the data site to witness traffic connection has a minimum bandwidth of 2 Mbps for every 1,000 vSAN components. May 31, 2018 · If there is an Availability Zone failure while the vSAN Witness Host was inaccessible vSAN wouldn’t have sufficient votes to maintain access and would preemptively shut down the workload to protect against any potential split-brain scenario. The standalone host is indeed licensed with a vSphere 7 Standard license. Has anyone run across this? It is for our college lab and we have licenses but no VMWare support contract. If you want to clone a VM witness host to support multiple stretched clusters, do not configure the VM as a witness host before cloning it. Sep 8, 2020 · I have been revisiting the vSAN network and how the vSAN network is configured. I deployed vCenter 7 appliance 2. Host 2 (DELL server) doesn't have this warning. As part of the lab I run nested vSAN On the Select witness host page, select a host to use as a witness host. Gather Required vSAN Cluster Information Identify all nodes within the vSAN cluster, including their management IP addresses. Also make sure that all vSAN configuration in vCenter is accurate (including host fault domain settings, de-duplication settings, encryption settings, Automatic Rebalance and so on) because any mis-configuration pushed down at this stage can reconfigure For an OSA witness, the first time you configure vSAN with a witness host you will claim the disks used by the witness, when adding additional clusters this step is skipped. dyxxoi yfukt wrifb sjrj aqgmj cbqqq cvfp rlqxu gqobtm ephnv byon jemlr quqx nlwtu kpomh