Quoting Michael H. Warfield (m...@wittsend.com): > On Fri, 2013-06-07 at 08:45 +0000, Purcareata Bogdan-B43198 wrote: ... > I use to do something similar a lot under the old linux-vservers project > (now defunct for several years - mailing list is now dead). They used a > COW (Copy On Write) system to maintain a common READ ONLY root system > and per-vserver modified layers of changes each server made while > running. It was quite a nice feature. > > In theory, this is the idea of using a rootfs image with a unionfs rw > layer on top of that for the running container. That way, you only have > one copy of a binary on disk and only one copy of the shared executable > code in memory, yet the containers all have unique modifiable root file > systems. So it works in principle. Implementation can be another > matter. > > I think I recall having done this with OpenVZ (after linux-vserver > failed in ongoing IPv6 support forced me over to OpenVZ) but that also > would have been a long time ago. More recently (but still more than a > year ago) I tried the same technique using unionfs with LXC which failed > horribly. Functionally, it should appear to be similar to a bind mount > but bind mounts are currently problematical with some of the hacks we've > had to implement to work around systemd conventions. I haven't tried it > in well over a year. I suppose I should try that again. Maybe it would > work now...
This is (IIUC) what lxc-start-ephemeral is meant to do - and also what 'lxc-clone -B overlayfs -o containerbase -n containerA' is meant for, where containerbase is a canonical, directory-backed container which all other containers are based upon, and containerA becomes a usable container with an overlayfs or aufs write layer mounted over containerbase's readonly rootfs. It's how both docker and https://github.com/hallyn/lxc-snap provide incremental container image development. -serge ------------------------------------------------------------------------------ How ServiceNow helps IT people transform IT departments: 1. A cloud service to automate IT design, transition and operations 2. Dashboards that offer high-level views of enterprise services 3. A single system of record for all IT processes http://p.sf.net/sfu/servicenow-d2d-j _______________________________________________ Lxc-users mailing list Lxc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lxc-users