|OS type and version|Ubuntu Linux 24.04.4|
|Webmin version|2.641|
|Virtualmin version|8.1.0 Professional|
|Webserver version|Apache/2.4.58 (Ubuntu)|
I run my virtualmin in proxmox these days, i am planning on migrating from Ubuntu to Debian and am curious if there are any downsides to running the Debian in an LXC container.
No, Debian is an excellent distro choice, after all Ubuntu itself is based upon it.
Are there any specific pain points you anticipate or are considering?
Ahh… i really need to phrase my questions a bit better, I am super happy with Debian even more so as it is snap free, but i have always run them as QEMU vms rather than LXC containers… the question was supposed to ask for any takes on using LXC containers rather than QEMU virtual machines in a Proxmox environment as i believe that LXC is more efficient / uses less resources.
If all your vms are Debian or Ubuntu then containers (LXC) will be more resource friendly as they utilize the same kernel making them lighter.
If you’re running other OS’ like Windows or you need further isolation or tighter security and resource mapping then utilize a VM.
I’ve found in my Linux only environment that containers are far more efficient without any negatives compared to full VMs.
I’d say spin up some containers, test them against their VM siblings and see for yourself the differences and what works best for you. You CAN have both co existing.
KVM has extremely effective page sharing (memory pages will be shared between VMs, including kernel and applications/libraries) via KSM (Kernel Same-Page Merging). You’re probably not saving a lot of resources by using LXC, if any, on modern Linux systems, especially if the systems are all similar. https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/7/html/virtualization_tuning_and_optimization_guide/chap-KSM
And, LXC has remarkably fewer developers and less investment behind it. It’s not bad software, but it’s a neglected step-child compared to KVM, which is in use at nearly all major VM providers (except AWS which uses Xen) and supported by all major Linux distros.
We’re in the process of removing container support from Cloudmin, as the reasons for using it over fully virtualized systems with KVM aren’t really relevant, anymore. You’ll probably get similar resource usage from either and KVM will very likely be more secure and reliable, due to much broader usage and more active/funded development. A few years ago, there was a good case to be made for containers if you needed lightweight virtualized systems, but I don’t think you can really make that case anymore.
If you already have everything running nicely with KVM (Qemu doesn’t tell us what backend you’re using…there is Qemu for Xen, KVM, and several others), you should probably just make sure KSM is enabled and configured appropriately for your system. That’d likely give you similar gains to switching to containers.