On 26.01.2021 18:41, Scott Dowdle wrote:
Have you tried LXD?
Not yet. My first post on this mailing list asked if anyone was using LXC in production: Does anyone use LXC and/or systemd-nspawn containers on RHEL 8 / CentOS 8 for production? What are advantages and disadvantages of each of these technologies? Can you share your experience with LXC and/or systemd-nspawn for RHEL 8 / CentOS 8 operating system on the hardware node? ============================================================
podman is replacement for Docker, it is not replacement for OpenVZ 6 containers.
Docker definitely targets "Application Containers"... with one service per container. podman says they can also do "System Containers" by running systemd as the entry point. Of course the vast majority of pre-made container images you'll find in container image repositories aren't built for that, but you can use distro provided images and build a system container image out of them. I have a simple recipe for Fedora, CentOS, and Ubuntu. I don't know how many people are using podman in this capacity yet, and I don't know if it is mature or not for production... but the limited testing I've done with it, has worked out fairly well... using Fedora or CentOS Stream 8 as the host OS...
No problem, systemd-nspawn also has worked out fairly well, without extra complexity, introduced by podman "System Containers" images.
Yes, podman does still use it's own private network addressing, but I guess that can be overcome by telling it to use the host network. I haven't tried that. Not exactly like OpenVZ's container networking for sure.
I can't use host network for [system] containers. Each container must have its own private network.
I have containers with 1.6 TiB of valuable data - podman not designed to work in this mode and in such conditions.
Persistent data really isn't an issue. You just have to understand how it works. Plenty of people run long-term / persistent-data Docker and podman containers...
Backuping persistent containers and restoring from backup - issue. I don't want have deal with a mash of different images and layers. Each my systemd-nspawn container located in separate filesystem: # zfs list NAME USED AVAIL REFER MOUNTPOINT tank 531G 1.13T 96K /tank tank/containers 528G 1.13T 168K /tank/containers tank/containers/1 19.1G 1.13T 8.00G /tank/containers/1 tank/containers/100 7.59G 1.13T 6.59G /tank/containers/100 tank/containers/111 169G 1.13T 27.6G /tank/containers/111 tank/containers/120 3.05G 1.13T 1.31G /tank/containers/120 tank/containers/121 10.2G 1.13T 9.20G /tank/containers/121 tank/containers/122 8.80G 1.13T 7.23G /tank/containers/122 tank/containers/124 3.20G 1.13T 2.21G /tank/containers/124 tank/containers/125 3.08G 1.13T 2.12G /tank/containers/125 tank/containers/126 87.1G 1.13T 64.1G /tank/containers/126 tank/containers/127 145G 1.13T 125G /tank/containers/127 tank/containers/128 7.46G 1.13T 5.62G /tank/containers/128 tank/containers/129 6.04G 1.13T 3.92G /tank/containers/129 tank/containers/130 5.03G 1.13T 3.01G /tank/containers/130 tank/containers/131 6.41G 1.13T 2.94G /tank/containers/131 tank/containers/132 4.55G 1.13T 2.98G /tank/containers/132 tank/containers/133 22.7G 1.13T 20.6G /tank/containers/133 tank/containers/134 3.36G 1.13T 1.61G /tank/containers/134 tank/containers/135 3.82G 1.13T 1.73G /tank/containers/135 tank/containers/25 1.74G 1.13T 960M /tank/containers/25 tank/containers/30 2.15G 1.13T 1.35G /tank/containers/30 tank/containers/97 5.90G 1.13T 2.06G /tank/containers/97 tank/containers/99 3.15G 1.13T 2.20G /tank/containers/99 Each filesystem has many snapshots (24 hourly and 30 daily), which are replicated to backup server, without the need to stop each systemd-nspawn container for creating snapshot/backup of it.
So I have only two alternatives for OS-level virtualization: LXC or systemd-nspawn.
If CentOS is your target host, I'd guess that neither of those really are a good solutions... simply because they aren't supported and upstream doesn't care about anything other than podman for containers.
Upstream also doesn't support ZFS, but this is extraordinary file system with excellent feature set.
LXC varies from one distro to the next... with different kernels, and different versions of libraries and management scripts. Again, LXD on an Ubuntu LTS host is probably the most stable... with Proxmox VE as a close second. Both of those upstreams care about system containers and put in a lot of effort to make it work.
LXC/LXD for CentOS 8 and other Linux distros distributed in the form of snap package. Inside snap - ordinary Ubuntu. Google "Install LXC CentOS 8" for more details about this.
Good luck.
Thank you. Luck is need for me to find solutions of these bugs: https://bugzilla.redhat.com/show_bug.cgi?id=1913734 https://bugzilla.redhat.com/show_bug.cgi?id=1913806 -- Best regards, Gena _______________________________________________ CentOS-virt mailing list CentOS-virt@xxxxxxxxxx https://lists.centos.org/mailman/listinfo/centos-virt
