3 ms·

Excuse me, but isn't this essentially chroots reinvented?

• VLM 12y ago
  That is exactly it, with a couple more isolation features added. So more than just the FS but also some memory / cpu limiting and general sandboxing. Interestingly most "real virtualization" requires somewhat recent hardware but LXC containers don't take much if any, so "free machine off junk heap" is good enough for experimentation. Historically there have been strange intercontainer isolation problems so don't assume its as perfect as hardware assisted virtualization. Also you're sharing a kernel which is both good and bad, if you were hoping to test out a new kernel or run an entirely different OS, thats too bad. Edited to add, another fun analogy if you like the chroot analogy, is when spinning up a process was glacial on windows (but not too bad on linux) that lead to the development and push to use threads which were a huge win on slow windows not so much on linux but we got dragged along anyway. In a similar manner, full virtualization is really slow to deploy and spin up and spin down, containers are smaller and weaker but much like threads vs processes are much faster to start up or shutdown. A really low latency or fast spinup spindown virtualization tech would probably wipe most demand for containerization. Or what I'm getting at is, spawning processes on windows was super slow, so we got threads, and spawning full hardware virt is slow, so we get containerization aka chroot++
  • Svenstaro 12y ago
    Alright, thanks a lot for the explanation then! Then my concept wasn't entirely wrong.