On 10/06/2010 09:46 AM, Helmut Lichtenberg wrote: > Hi, > I have a question concerning the practical use of lxc containers. > > Currently we have lots of complete virtual machines (kvm and xen) for services > like fileserver/samba, dhcp/cups, ldap/kerberos, terminalserver, > computecluster, etc. on about 10 hardware machines (mostly recent 2-socket > quadcores). This serves about 60 concurrent users in our research institute. > > As hardware gets more and more powerful, I would like to reduce the number of > virtual machines (to make my life easier :^). > Currently we reach the state to provide most of the services for the users > like file- and terminalservices on *one* hardware machine (2-socket sixcore > with X5680 CPU @ 3.33GHz), apart from any redundancy. > > My plan is to create really tiny containers to separate the services, and > concentrate most of then on one machine. > > In a test container, I readonly bind-mounted the directories > /usr > /bin > /sbin > /lib > /lib32 > /var/lib/dpkg > into lxc which leads to about 200MB size of the remaining lxc-tree. > > The problem appeared, that this does not work out of the box. > Simple programs like atd don't work as e.g. the directories > /var/spool/cron/atjobs/ and /var/spool/cron/atspool/ do not exist, just as > /etc/init.d/atd. They have been created on the host during installation. > > This is just a simple example, but in general, most of the programs in /usr, > /bin, etc. have configurations in /etc and leave traces in /var during > installation. > > Does anybody use such an appealing setup and how can one handle this problem? >
Maybe you can use unionfs or aufs on top of /var/spool and /etc/init.d, no ? Another alternative, more experimental, would be to install a distro in an btrfs image file. You can create a snapshot for each container and use this snapshot as the rootfs for a container. As this filesystem is a COW, the 'atd' container will have its private data in /var/spool. Moreover, the initial image can be used as a backup installation as it will be never modified. ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today. http://p.sf.net/sfu/beautyoftheweb _______________________________________________ Lxc-users mailing list Lxc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lxc-users
