Managing resource limits in an OpenVZ container involves several steps, all of which must be performed as the root user on the hardware node. Here is a brief outline of the process:
1. Identify the Container ID: To manage resource limits, you first need to identify the ID of the container you wish to modify. This can be done using the “vzlist” command, which provides a list of all active containers.
1. Stop the Container: To ensure that no processes are interrupted, it’s crucial to stop the container before modifying any resource parameters. This can be accomplished with the “vzctl stop” command followed by the container ID.
1. Modify Resources: OpenVZ has a configuration file for each container located at /etc/vz/conf/ID.conf, where the ID is the container ID. This file contains various parameters like CPU usage, memory usage, disk usage, etc. You can adjust these parameters to limit the usage of resources.
Examples of these parameters:
- PRIVVMPAGES: The limit of private (i.e., not shared) memory that can be used by a container;
- NUMPROC: The maximum number of process container can have;
- DISKSPACE: The limit of disk space container can use;
This file can be edited using a text editor such as nano or vi. For example, to set the disk space limit to 10GB, you can modify it like this:
DISKSPACE=“10G:11G”The first value is the soft limit, and the second one is the hard limit.
1. Apply Changes: After making the necessary modifications, save the configuration file and exit the text editor. To apply these changes, you need to restart the container using the command “vzctl start” followed by the container ID.
1. Check Changes: You can check if the changes have been applied using the “vzctl exec” command followed by the container ID and the “free -m” command. This will display the memory available in the container.
Note: These steps assume a level of familiarity with Linux-based operating systems and command-line interfaces. If you’re not comfortable working in such an environment, you might want to consider seeking the help of a system administrator or a well-versed colleague. Also, remember to consider the overall performance and stability of your system when adjusting container resource allocations.
