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Lab 16.1 LXC on CentOS 7 - container will not start

I've successfully progressed to point 8 in Lab 16.1 - 'Start the container' (there were a few errors with the instructions that I've noted below in 'Additional Steps') but have ran into an error when trying to start the container.

At this point when I execute lxc-start -n bucket an error is returned.

lxc_container: lxc_start.c: main: 290 Executing '/sbin/init' with no configuration file may crash the host

The result is that the process exits and their is no trace left of the container.

The container is not listed when executing lxc-ls -f

Attempting to destroy the container and start from 16.1.1

$ lxc-destroy -n bucket
Container is not defined

Additional Steps (CentOS7)

  • lxc-ls is not bundled with lxc, it is part of the lxc-extra package. This package is not listed to be installed in 16.1.1

Answers

  • lee42xlee42x Posts: 237
    edited September 24

    Hi GRO108,

    Sorry for missing the CentOS7 "lxc-extra" package, that will get fixed.

    Now your issue with the containers, puzzling as I just did the steps 16-1 through 16-9 on my CentoOS7 VM. Were you successful with step 16-6? Are you executing the lxc commands as root or regular user? Which kernel are you using on the base machine running the containers?

    Here is an example of mine using the lxc-ls command.

    [[email protected] ~]$ lxc-ls -f

    NAME STATE IPV4 IPV6 AUTOSTART

    [[email protected] ~]$
    [[email protected] ~]$ sudo lxc-ls -f

    NAME STATE IPV4 IPV6 AUTOSTART

    bucket RUNNING 192.168.124.248 - NO
    bucket1 STOPPED - - NO
    bucket8 RUNNING 192.168.124.199 - NO
    [[email protected] ~]$

  • GRO 108GRO 108 Posts: 46

    Hi @lee42x ,

    I've gone back over the steps and realised I've missed step 4. (I have added the file /etc/sysconfig/lxc-net)

    Start the LXC network service and make it start on initialization automatically.
    # systemctl enable --now lxc-net

    When I execute that I receive the error.

    Failed to execute operation: No such file or directory

    I checked my unit files and noticed that lxc was not enabled so I did that.

    $ sudo systemctl enable --now lxc
    $ sudo systemctl daemon-reload
    $ systemctl list-unit-files --state=enabled | grep lxc
    lxc.service                                enabled
    

    I had a dig around for any packages or manual references for lxc-net and didn't come across any.

    My kernel (of the host) is: Linux version 3.10.0-1127.10.1.el7.x86_64

  • lee42xlee42x Posts: 237

    Here is a reference for lxc-net, scroll down to the "independent bridge setup" :
    [https://wiki.debian.org/LXC#Networking_Essentials]

    This file instructs lxc to create a Linux network bridge. An independent bridge is used so the class does not conflict with any existing networking on your system.

    Regards Lee

  • AlexeyBYAlexeyBY Posts: 31

    Hello all,
    I've got the same mistake (CentOS7/kernel 3.10) --- > systemctl enable lxc-net --> Failed to execute operation: No such file or directory. I will use the "independent bridge setup". thank you for the link. I suggest correcting the lab :)

    Regards

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