HPE SimpliVity is a hyperconverged infrastructure (HCI) solution that integrates compute, storage, and virtualization resources into a unified platform. When deployed with VMware vSphere, HPE SimpliVity relies on several OmniStack management services to maintain communication between infrastructure components, monitor system health, and report operational events.
Although SimpliVity environments are designed to provide reliable infrastructure services, administrators may occasionally encounter communication-related alarms in VMware vCenter Server.
One of these alarms is:
SimpliVity – HPE OmniStack host lost connection to the Eventmgr
This warning indicates that an HPE OmniStack host has lost communication with the Event Manager component responsible for processing and reporting infrastructure events.
In many cases, the virtual machines and underlying storage infrastructure may continue operating normally, while certain management and monitoring functions become unavailable or unreliable.
This article explains the possible causes of the Eventmgr connectivity error, how to diagnose the issue, and the troubleshooting procedures that can help restore communication between the affected components.
Understanding the Eventmgr Connection Error
The Event Manager (Eventmgr) is an important component of the HPE SimpliVity management architecture. It processes infrastructure events and helps communicate operational information to the management layer.
When communication between an OmniStack host and Event Manager is interrupted, VMware vCenter Server may generate the following alarm:
SimpliVity - HPE OmniStack host lost connection to the Eventmgr
This condition does not necessarily indicate a physical hardware failure or an immediate storage outage.
Instead, it typically indicates a communication problem involving one or more SimpliVity management components.
Depending on the underlying cause, the issue may affect event reporting, monitoring visibility, and certain management operations.
Common Causes
Several conditions may trigger this alarm:
- Event Manager service failure: The Event Manager process may stop unexpectedly, become unresponsive, or fail to communicate with other management services.
- OVC management service issues: Communication between services running on the OmniStack Virtual Controller (OVC) may become interrupted.
- Network connectivity problems: Management network interruptions between ESXi hosts, OVC appliances, management components, and vCenter Server may prevent normal communication.
- Management appliance availability: In environments using a Management Virtual Appliance (MVA), the appliance may be powered off, unavailable, or experiencing connectivity problems.
- Temporary service or resource problems: High resource utilization, service failures, or transient communication errors may affect management operations.
If the same alarm appears simultaneously on multiple SimpliVity hosts, the underlying issue may involve a shared management component or common network dependency rather than an individual ESXi host.
Identifying the scope of the problem is therefore an important first step.
Identifying the Alarm in VMware vCenter Server
The Eventmgr connectivity alarm is typically displayed in the VMware vSphere Client.
To investigate the issue, log in to vCenter Server and locate the affected HPE SimpliVity ESXi host.
Navigate to:
vSphere Client → ESXi Host → Monitor → Issues and Alarms
Depending on the vSphere Client version, the alarm may also appear in the host’s Summary or triggered alarms view.
The following message may be displayed:
SimpliVity - HPE OmniStack host lost connection to the EventmgrBefore performing any corrective actions, review the alarm details and determine:
- When the alarm was first triggered.
- Whether the issue affects one or multiple hosts.
- Whether any OVC appliances were recently restarted.
- Whether network configuration changes occurred.
- Whether other SimpliVity management or storage-related alarms are present.
Reviewing the sequence of events can help distinguish a temporary management communication failure from a broader infrastructure problem.
Verify OVC, MVA, and Management Network Connectivity
Before restarting any services, verify that the required SimpliVity management components are operational.
Check the OmniStack Virtual Controller
Each affected SimpliVity host should have its associated OmniStack Virtual Controller available and functioning correctly.
Using the vSphere Client, verify that the relevant OVC virtual machine is powered on and accessible.
If the environment uses a separate Management Virtual Appliance, confirm that it is also running and accessible.
A management appliance that is powered off, disconnected, or experiencing network problems may prevent normal communication with the underlying infrastructure.
Test Network Connectivity
Once the management appliances have been verified, test communication between the relevant infrastructure components.
Enable SSH on the affected ESXi host if permitted by your operational security policy, then establish a connection.
To test connectivity to the MVA, where applicable, run:
vmkping <MVA_IP_ADDRESS>Alternatively, test connectivity to the relevant OVC management address:
vmkping <OVC_MANAGEMENT_IP>The vmkping utility tests connectivity using the ESXi VMkernel networking stack.
If the environment uses multiple VMkernel interfaces or separate TCP/IP stacks, ensure that the test uses the appropriate source interface or network stack.
If connectivity fails, investigate the following components:
- VMkernel network configuration.
- VLAN assignments and network segmentation.
- Routing and gateway settings.
- Firewall or access control rules.
- Physical and virtual switch connectivity.
- Management IP addressing.
If network communication is functioning normally, continue by examining the OmniStack management services.
Check the HPE OmniStack Version Before Restarting Services
One of the most important considerations when troubleshooting Eventmgr connectivity problems is identifying the installed HPE OmniStack version.
Service names and management procedures have changed between OmniStack releases.
Consequently, commands that work on older versions may not be supported on newer releases.
Important: Do not restart OmniStack services in a production environment without first verifying the installed version and confirming the supported procedure in the corresponding HPE documentation.
Restarting certain infrastructure services, particularly HyperProxy-related components, may affect management functionality and potentially introduce operational risks.
The following examples describe service management procedures associated with specific older OmniStack versions.
They should not be treated as universal restart procedures for every SimpliVity release.
Restarting Management Services on Older OmniStack Versions
HPE OmniStack 3.7.7 and Earlier
On older OmniStack versions, the Event Manager service may be managed separately from other management components.
Where supported by the installed release, the following commands can be used to stop the relevant services in sequence:
stop svt-event-manager
stop svt-hyperproxy-server
stop svt-restAfter the services have stopped, they can be started in the following order:
start svt-hyperproxy-server
start svt-event-manager
start svt-restThe purpose of this sequence is to allow the relevant services to initialize and re-establish communication.
Wait for the services to become operational before proceeding with further troubleshooting.
Do not repeatedly execute the restart sequence if a service fails to start. Instead, investigate the failure and review the relevant logs.
HPE OmniStack 3.7.8
In OmniStack 3.7.8, changes to the management service architecture may require the use of svt-controlservices instead of the standalone Event Manager service.
For environments where this legacy service management method is supported, the following stop sequence may apply:
stop svt-controlservices
stop svt-hyperproxy-server
stop svt-restOnce the services have stopped successfully, they can be started in the following order:
start svt-hyperproxy-server
start svt-controlservices
start svt-restThis sequence is intended to restore communication between the relevant OmniStack management components.
However, the exact service structure must be confirmed against the installed version and its supported maintenance procedures.
HPE OmniStack 3.7.10 and Later
Newer OmniStack releases may use systemd for service management.
In these environments, the older stop and start commands may no longer be applicable.
Before performing a restart, connect to the OVC appliance through SSH and list the available SimpliVity services:
systemctl list-units --all --type=service | grep svtThis command displays matching services without modifying their operational state.
To inspect the REST service, execute:
systemctl status svt-rest.serviceIf the REST service requires a restart and the procedure is supported by the installed OmniStack release, the following command may be used:
systemctl restart svt-rest.serviceNote: Restarting svt-rest.service only addresses the REST service. It does not guarantee that an Event Manager communication problem will be resolved.
The appropriate Event Manager or control service restart procedure must be determined from the installed release documentation.
Avoid restarting multiple OmniStack services without first identifying the affected component and evaluating the potential impact.
Allow the Event Manager Connection to Recover
After the required management services have been restored, allow several minutes for communication between SimpliVity components to re-establish.
During this period, the management services may need time to initialize, reconnect, and resume normal event processing.
Return to the vSphere Client and navigate to the affected host’s alarm view.
When the Event Manager connection is successfully restored, the following event may be generated:
Eventmgr Reconnected
Event identifier:
com.simplivity.event.control.eventmgr.reconnectedThis event indicates that the Event Manager connection has been re-established.
When the corresponding recovery event is processed successfully, the original connectivity alarm may clear automatically.
However, administrators should not rely solely on the disappearance of the alarm.
It is also important to confirm that the relevant OmniStack services are operational and that SimpliVity management functionality has returned to its expected state.
Additional Troubleshooting if the Alarm Persists
If the Eventmgr alarm remains active after verifying network connectivity and management service availability, additional investigation may be required.
Review OVC Service Logs
Inspect the relevant OmniStack service logs and system journal entries for communication failures, repeated service restarts, or unexpected process termination.
On releases using systemd, the following command can help review recent REST service messages:
journalctl -u svt-rest.service -n 100 --no-pagerThis command displays recent journal entries associated with the REST service without changing its state.
Keep in mind that REST service logs may not contain the underlying cause of an Event Manager-specific problem.
Other service logs should be reviewed according to the affected component and installed OmniStack version.
Verify DNS and Time Synchronization
Management communication can be affected by incorrect name resolution or significant differences in system time.
Verify that the relevant infrastructure components have consistent DNS configuration and synchronized clocks.
Pay particular attention to:
- Forward and reverse DNS resolution.
- NTP configuration.
- Time differences between management appliances.
- Hostname and IP address consistency.
These checks can help identify environmental issues that may contribute to management communication failures.
Examine vCenter Connectivity
Confirm that the relevant SimpliVity management components can communicate with VMware vCenter Server.
If the issue began after a vCenter upgrade, certificate replacement, or management network change, review those changes carefully.
Depending on the architecture and release, certificate or authentication issues may prevent certain management operations from completing successfully.
Determine Whether Multiple Hosts Are Affected
If only one SimpliVity host reports the error, prioritize its associated OVC, management connectivity, and service health.
If multiple hosts report the same alarm simultaneously, investigate common dependencies such as management network infrastructure, shared management services, and vCenter connectivity.
This approach helps narrow the investigation and reduces unnecessary service disruption.
Verification After Troubleshooting
After completing the corrective actions, perform a final health check of the SimpliVity environment.
Confirm that the OVC virtual machines are powered on and accessible, the relevant management services are running, and the affected ESXi hosts remain connected to vCenter Server.
Verify that the Eventmgr connectivity alarm is no longer active or that a corresponding recovery event has been generated.
In addition, confirm that normal SimpliVity management and monitoring operations are functioning correctly.
If the alarm repeatedly returns, avoid clearing it manually as a substitute for investigating the underlying cause.
Repeated Event Manager communication failures may indicate an unresolved service, networking, or management infrastructure issue.
For persistent problems, collect the relevant logs, affected host information, OmniStack version, and alarm timestamps before opening a support case with HPE.
Best Practices for Preventing Similar Issues
Maintaining reliable communication between OmniStack management components is essential for stable SimpliVity operations.
Administrators should periodically review infrastructure health, management network connectivity, and the operational status of critical services.
It is also advisable to maintain accurate documentation of the installed OmniStack version, vCenter compatibility, management IP addresses, and supported maintenance procedures.
Before performing upgrades, network modifications, or certificate changes, evaluate potential dependencies between SimpliVity management components.
Finally, avoid unnecessary restarts of OmniStack infrastructure services in production environments. Such operations should follow a validated troubleshooting or maintenance procedure appropriate for the installed release.
The “HPE OmniStack host lost connection to the Eventmgr” alarm indicates that communication between an HPE SimpliVity host and the Event Manager component has been interrupted.
Although this condition does not necessarily represent an immediate storage or virtual machine outage, it can affect management visibility and event reporting within the SimpliVity environment.
The recommended troubleshooting approach begins by verifying the availability of the OVC and applicable management appliances, followed by checking network connectivity and the operational state of OmniStack management services.
If a service-related problem is identified, the appropriate recovery procedure should be selected according to the installed HPE OmniStack version.
Once communication is restored, the Eventmgr Reconnected event may be generated, allowing the associated connectivity alarm to clear automatically.
By following a structured troubleshooting process and avoiding unnecessary service restarts, administrators can restore management connectivity while minimizing operational risk to their HPE SimpliVity infrastructure.
