11.3. Container Management Issues

This section includes recommendations on how to solve certain container issues.

11.3.1. Failure to Start a Container

An attempt to start a container fails.

Solution 1

If there is a message on the system console: IP address is already used, issue the cat /proc/vz/veinfo command. The information about the container numeric identifier, container class, number of container’s processes and container IP address shall be displayed for each running container. This shall also demonstrate that your container is up, i.e. it must be running without any IP address assigned. Set its IP address using the command:

# prlctl set <CT_name> --ipadd <IP_address>

Where <CT_name> is the container name and <IP_address> is the desired IP address.

Solution 2

The container might be configured incorrectly. Try to validate the container configuration and find out what parameters have caused the error. Set appropriate values using the prlctl set command.

Solution 3

The container might have used all its disk quota (disk space). Check the quota (see Managing Disk Quotas) and adjust its parameters if needed.

Solution 4

Run the prlctl console utility to log in and get access to the container console. The utility will provide container startup/shutdown output that may be used to pinpoint the problem. For example:

# prlctl console MyCT

Where MyCT is the container name.

11.3.2. Failure to Access a Container from Network

Solution 1

The IP address assigned to the container might be already in use in your network. Make sure it is not. The problem container address can be checked by issuing the following command:

# grep IP_ADDRESS /etc/vz/conf/<UUID>.conf

The IP addresses of other containers, which are running, can be checked by running

# cat /proc/vz/veinfo

Solution 2

Make sure the routing to the container is properly configured. Containers can use the default router for your network, or you may configure the hardware node as router for its containers.

11.3.3. Failure to Log In to a Container

The container starts successfully, but you cannot log in.

Solution 1

You are trying to connect via SSH, but access is denied. Probably you have not set the password of the root user yet or there is no such user. In this case, use the prlctl set --userpasswd command. For example, for the container MyCT you might issue the following command:

# prlctl set MyCT --userpasswd root:secret

Solution 2

Check forwarding settings by issuing the following command:

# cat /proc/sys/net/ipv4/conf/venet0/forwarding

If it is 0 then change it to 1 by issuing the following command:

# echo 1 > /proc/sys/net/ipv4/conf/venet0/forwarding