[lxc-users] Container scaling - LXD 2.0

[Mark Constable]

On 09/05/16 10:18, Ronald Kelley wrote:
> I am trying to get some data points on how many containers we can
> run on a single host if all the containers run the same applications
> (eg: Wordpress w/nginx, php-fpm, mysql). We have a number of LXD 2.0
> servers running on Ubuntu 16.04 - each server has 5G RAM, 20G Swap,
> and 4 CPUs.

I want to do almost exactly this too, plus owncloud.

> I have read about Kernel Samepage Memory (KSM), and it seems to be
> included in the Ubuntu 16.40 kernel. So, in theory, we can over
> provision our containers by using KSM.

Excellent point, I am also keen to know if KSM can help with this kind
of setup. My thoughts had been to run a single instance of MySQL (or
Mariadb) in it's own container because a couple of dozen instances of
MySQL (with Innodb) takes up at least 100Mb each so running a single
instance of MySQL would definitely help but if KSM is a real thing
with containers then it may not be necessary to consider such
workarounds.