vSAN cluster alarm 'vSAN cluster compliance'

Products

• VMware vSAN

Issue/Introduction

vSAN cluster alarm 'vSAN cluster compliance'

An alert message, vSAN cluster alarm 'vSAN cluster compliance', might pop up after the successful upgrade from v8.0.3.00400 to v8.0.3.00500

vCenter vmware-vsan-health-summary-result.log shows:

Test vsanesacompliancecheck health : yellow
         ComplianceStatus: HealthStatus  ComplianceIssue  Recommendation
Yellow,TheResyncTrafficOptimizationIsNotEnabled.WhenVsanEsaIsRunningInEnvironmentsWith10GbeNetworkingInfrastructure,UnderCertainConditionsResynchronizationTraffic(DueToMaintenanceMode,CapacityRebalance,PolicyChange,OrFaultRecovery)MayCauseAnImpactToVmIoTrafficBeyondThe20%TargetThatAdaptiveResyncAttemptsToEnforce.GuestLatencyMayIncreaseAsAResult,SetTheVsanAdvancedOptionOnAllHostsWithTheEsxiCommandLine:EsxcliSystemSettingsAdvancedSet-I1-O/Vsan/Domnetworkschedulerthrottlecomponent),
         HostConfigurationDetails: Host  ResyncOptimizationEnablement
                                   (Host-######, 0(Disabled)), (Host-######, 0(Disabled)), (Host-######, 0(Disabled)),

Environment

vSAN ESA 8.0U2 and later versions.

Cause

A new online health check was added recently that affects all versions of ESA when configured on 10G networks since 25G is recommended for vSAN ESA Configuration.

This affects all versions of ESA when configured on 10G networks. Support for 10G networking was only added in vSAN 8.0 U2. 

Resolution

There is no currently released version which contains a fix, so the below workaround is recommended.

Workaround:

The option /VSAN/DOMNetworkSchedulerThrottleComponent must be set to 1 on all ESX hosts in the cluster to resolve the issue.

This can be changed via the following ESXi cli command. 

# esxcfg-advcfg -s 1 /VSAN/DOMNetworkSchedulerThrottleComponent

 

Additional Information

The config option is available in all versions of ESX which support ESA (namely ESX 8.0 onwards). The configuration option can be set on a running host. The effect will be immediate and persistent. Setting the config on hosts with networking faster than 10G will not cause functional issues but may result in suboptimal resynchronization throughput.

vSAN Health Service - Online health - vSAN Cluster Compliance