[CentOS-virt] OS-level virtualization using LXC and systemd-nspawn containers

Mon Jan 25 22:05:24 UTC 2021
Scott Dowdle <dowdle at montanalinux.org>


----- Original Message -----
> OpenVZ 7 has no updates, and therefore is not suitable for
> production.

The free updates lag behind the paid Virtuozzo 7 version and plenty of people are using it in production.  I'm not one of those.

> LXC/LXD is the same technology, as I understand from
> linuxcontainers.org

linuxcontainers.org is owned by Canonical and yes it documents LXC... but LXD is a management layer on top of it which provides for easy clustering and even managing VMs.  I think it is the closest thing to vzctl/prlctl from OpenVZ.

> podman can't be a replacement for OpenVZ 6 / systemd-nspawn because
> it destroys the root filesystem on the container stop, and all
> changes made in container configs and other container files will be lost.
> This is a nightmare for the website hosting server with containers.

No, it does NOT destroy the delta disk (that's what I call where changes are stored) upon container stop and I'm not sure why you think it does.  You can even export a systemd unit file to manage the container as a systemd service or user service.  volumes are a nice way to handle persistence of data if you want to nuke the existing container and make a new one from scratch without losing your data.  While it is true you have to approach the container a little differently, podman systemd containers are fairly reasonable "system containers".
Scott Dowdle
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