To prevent unauthorized intrusion and misuse of ESXi servers, you can take the following comprehensive preventive measures.

Ensure that VMware ESXi is updated regularly, ESXI hosts are updated regularly, and the latest security and performance fixes are available. VWare regularly releases patches and updates to fix known issues.

Periodically back up VMS. You can create periodic VM backups to prevent data loss and quickly restore VMS when problems occur.

Pay attention to hardware usage. Hardware monitoring tools can be used to track the host's monitoring conditions, such as temperature, fan speed, power supply, etc., to identify potential hardware failures more quickly.

Allocate VM resources properly. Ensure that VM resources are properly allocated to avoid resource contention by assigning too many VMS to the same host.

Compatible virtual hardware is available. When creating a VM, you can select a virtual hardware version that is compatible with the ESXI version to ensure that the VM operating system supports the selected virtual hardware version.

You can enable VM monitoring. VMware provides the VM monitoring function to monitor VM performance and status. By enabling the monitoring function, you can detect faults in advance.

Use a firewall to ensure network security. Enable the built-in firewall of the ESXI server and deploy appropriate rules to restrict inbound and outbound connections to the server. Use virtual Lans to isolate and protect different network traffic, periodically review network configurations, and restrict remote access to servers.

Enable SSL/TLS encryption on the ESXI server. Implement encrypted communication. Ensure that the communication between the server is protected, and the connection can be encrypted through a secure protocol such as a virtual private network.

Only authorized users can log in to ESXI servers. You can use a strong password policy to periodically change the password to control the configuration access.

Implement monitoring and logging, and configure appropriate monitoring tools, logging, and auditing mechanisms to quickly detect and respond to security events.

Virtual security ensures that VMS running on ESXI servers are secure. Update the virtual operating system and software in a timely manner, use antivirus software to protect the VM environment, and restrict VM communication.

Periodically back up ESXI servers and VMS to prevent data loss caused by accidents and facilitate data recovery.

The above measures can significantly improve the stability and reliability of the ESXI server, and greatly reduce the possibility of faults.