1. Setting Limits: OpenVZ allows the host to set resource limits on the container, including CPU usage, disk space, and memory. You can use the vzct command to due this.
1. Monitoring: Continuously monitor the system resources consumed by the container. This includes things like CPU, memory, disk I/O, network traffic, etc. Use monitoring systems like Nagios, Zabbix, or even simple scripts with email notifications.
1. Use Fail2ban: It’s a log-parsing application that protects your virtual private server from bruce-force attacks.
1. Restrict Processes: You can specify a maximum number of processes that each container can run at a given time using the PROC parameter in the container configuration file.
1. Up-to-date system: Always keep your system updated. Regularly update your kernel, OpenVZ software, and all the packages within the containers.
1. Backup and Recovery: Regularly backup the container data to recover from potential crash or malicious attacks.
1. Regular Auditing: Regularly audit the container for any unusual activity or to identify resource-hungry processes.
1. Container Isolation: Isolate containers from each other, minimizing the risk of one badly behaved container affecting others.
1. Personal Firewalls: ensure every container has its own primary firewall, drastically reducing the risk of any overspill from one container to another.
1. Regular Restart: Schedule regular restarts of the container to clean up any stalled or zombie processes.
Prevention strategies may vary depending on the specific applications running within the container, the overall system architecture, and other factors. The above strategies serve as a starting point for creating a more extensive prevention and control strategy for your OpenVZ containers.