Sharing disk volumes across OpenVZ guests to reduce Package Management Overhead
- by andyortlieb
Is it feasible to create a single "master" OpenVZ guest who would only be used for package management, and use something like mount --bind on several other OpenVZ guests sort of trick them into using the environment installed by the master guest?
The point of this would be so that users can maintain their own containers, and yet stay in sync with the master development environment, so they'll always have the latest & greatest requirements without worrying too much about system administration. If they need to install their own packages, could put them in /opt, or /usr/local (or set a path to their home directory)?
To rephrase, I would like several (developer's, for example) OpenVZ guests whose /bin, /usr (and so on...) actually refer to the same disk location as that of a master OpenVZ guest who can be started up to install and update common packages for the environment to be shared by all of this group of OpenVZ guests.
For what it's worth, we're running Debian 6.
Edit:
I have tried mounting (bind, and readonly) /bin, /lib, /sbin, /usr in this fashion and it refuses to start the containers stating that files are already mounted or otherwise in use:
Starting container ...
vzquota : (error) Quota on syscall for id 1102: Device or resource busy
vzquota : (error) Possible reasons:
vzquota : (error) - Container's root is already mounted
vzquota : (error) - there are opened files inside Container's private area
vzquota : (error) - your current working directory is inside Container's
vzquota : (error) private area
vzquota : (error) Currently used file(s):
/var/lib/vz/private/1102/sbin
/var/lib/vz/private/1102/usr
/var/lib/vz/private/1102/lib
/var/lib/vz/private/1102/bin
vzquota on failed [3]
If I unmount these four volumes, and start the guest, and then mount them after the guest has started, the guest never sees them mounted.
