Both Linux Containers (or lxc as the project is known) and OpenVZ are lightweight virtualization systems that operate at the file system level, and as such can be attractive to people who are looking to split a big physical server into containers, while achieving resource isolation per container. I personally want to look into both primarily as a means to run several MySQL instances per physical server while ensuring better resource isolation , especially in regards to RAM.
In any case, I thought it would be interesting to post the replies I got on Twitter to my question.
"I just began using lxc. Have three hosts in it so far as a test run. Not doing NAT, just plain bridging right now."
"I just posted a short write up of how I use LXC on my laptop http://t.co/CQXTPMv"
"Have you tried lxc without libvirt? I found it to be a bit easier to deal with."
"Yes that is a red herring. You do not need libvirt. I had it installed already so went with it by default."
"It just helps me not have to set up dnsmasq, iptables etc. :-) But you can certainly do away with it."
"Have you tried doing an apt-get upgrade in lxc? What a PITA :)"
"btw, if you ever get to that point: http://t.co/2WvYaeX helped get me to a working solution"
"ive been using OpenVZ in production with Debian Stable (on the host and guests) for over a year with no problems...."
"@ichilton you had to recompile the kernel for OpenVZ support in Debian right?"
"I didn't, there was an OpenVZ kernel package but it was Lenny at the time and not upgraded yet - will have to check Squeeze."
"@vvuksan interested why you did that originally and what the advantages are in hindsight?"
"Speed. The dev env needs 5-6 boxes running at the same time and with Vbox my laptop becomes really slow. With LXC not so much."
"LXC should be considerably smoother in 11.10 for both 11.10/10.04 guests. I want to see laptop-based microclouds become common."
"@sstatik @griggheo Laptop based microclouds are the future. We're just missing quality software to help manage it."
"@sstatik @griggheo documentation and details getting better? its arcane to use in 11.04, and that is 1000x better than 10.x..."
So there you have it, a small snapshot of why and how people are using lxc/OpenVZ, especially on Ubuntu. I'll post my own experiences as I start playing with lxc and potentially OpenVZ.