Troubleshooting: ESXi Host Not Responding but VMs Still Running

In VMware vSphere environments, it is common to encounter issues where an ESXi host not responding while the virtual machines (VMs) running on it continue to function normally. This article explores the reasons why an ESXi host stops responding while a virtual machine continues to run, and provides guidance on how to diagnose and resolve the issue.

How to Solve ESXi Host Not Responding

The following part is a step-by-step troubleshooting for ESXi host not responding.

Check Host Resource Utilization

Sometimes the ESXi host does not respond due to high resource usage such as excessive CPU, memory, or disk usage. You can:

▶Access via the Direct Console Interface (DCUI):

If you have physical access to the host computer, check the host computer status on the DCUI (Direct Console User Interface). Look for any system alerts about high resource utilization or hardware issues.

▶Using the ESXi Shell or SSH: If you have SSH access to the host, use the following commands to check resource consumption:

esxtop (view CPU, memory, and disk performance in real time)

top (to see a snapshot of system resource usage)

▶Check logs for resource overloads: Check the logs for any resource-relate errors:

/var/log/vmkernel.log (kernel-related logs).

/var/log/hosted.log (host management log).

/var/log/vpxa.log (vCnter agent log).

Verify Network and Management Services

ESXi hosts rely on several management services, such as hosted and vpxa, to function properly. If these services fail, the host may not respond to management attempts but continue to run virtual machines. You can:

◆Restart the management services: If you can access the host through the console or SSH, restart the management services using the following command:

Or, specifically for the hosted and vpxa services:

◆Check the network configuration: Ensure the ESXi host has the correct configuration and can communicate with the management network. You can check the network configuration by running:

Checking Storage Connections

Failure to access shared storage (SAN or NAS) can cause the ESXi host to appear unresponsive while the ESXi host not responding but the virtual machine may still be using local storage or caching data. You can:

✦Check the storage status: Use the following command to check the storage connection:

✦Verify datastore accessibility: Use the ESXi web client or SSH to verify that the datastore is accessible and that there are no connectivity issues with the shared storage.

✦Check storage logs: Look for storage-related errors in the logs:

Checking Hardware and Hardware Compatibility

Hardware failures such as memory, network card, or other component failures can cause an ESXi host not responding. You can:

★Check Hardware Status: Verify the health of the hardware using the ESXi console or a physical management tool such as iLO, DRAC, or iDRAC.

★Check Hardware Alarms: Verify the health of the hardware in:

★Check Compatibility: Ensure that all hardware components are compatible with the version of ESXi you are running. For this, check the VMware Hardware Compatibility List (HCL) for that version.

A Powerful Backup Solution to Secure Virtual Machine Safe

An ESXi host is a physical server running the VMware ESXi hypervisor that virtualizes workloads and provides the foundation for running virtual machines in the datacenter. With the creation of numerous virtual machines, data security is a key consideration, and AOMEI Cyber Backup is a professional backup software that can manage numerous virtual machines. It is designed with data security, allowing you to back up your virtual machines in simple steps.

😊Easy to Use Interface: The intuitive interface allows you to connect, create tasks, and implement with just a few clicks.
✨Automated and Schedule Backups: Automatic and scheduled backups minimize the risk of data loss and simplify the backup process.
🎇Comprehensive Backup Options: You can create full, incremental, and differential backups enabling users to select the backup strategy that best fits their needs.
🔰Restore Entire VM: It can restore immediately available VMs from any selected restore points.

※You can hit the following button to download the 30-day free trial.

Simple steps to backup VMware ESXi VMs

Step 1. Log in to the AOMEI Cyber Backup Console, navigate to Source Device > VMware > + Add VMware Device to Add vCenter or Standalone ESXi, then enter Device Information and User Information and click Confirm.

Step 2. Navigate to Backup Task > + Create New Task, then set up Task Name, Backup Type, Device, Target, Archive, Schedule, and Backup Cleanup.

• Backup Type: Select VMware ESXi Backup as the Backup Type.

• Target: Select to backup to a local path, or to a network path.
• Archive: If you have an Amazon S3 storage, you can archive a backup version to it.
• Schedule: You can select full, differential, or incremental backup.

• Backup Cleanup: It can automatically delete old backup copies exceeding the specified backup retention period.

Step 3. Click Start Backup and select Add the schedule and start backup now, or Add the schedule only.

👉After creating a backup task, it is listed separately and monitored for checking progress, changing plans, and restoring. Clicking Restore to new location enables easy restoration of virtual machines in the same or other datastores/hosts without reinstalling or configuring new virtual machines.

Conclusion

When an ESXi host is not responding but VMs are still running, it can be due to a variety of reasons. However, systematic diagnosis of the underlying issue and examination of host logs, managed services, and hardware components are often effective in resolving the problem.