Hi, I was wondering if there was some way to use LVM to simulate the Copy-on-Write technique used in User Mode Linux. Basically, the idea is as follows: "The way to share a filesystem between two virtual machines is to use the copy-on-write (COW) layering capability of the ubd block driver. As of 2.4.6-2um, the driver supports layering a read-write private device over a read-only shared device. A machine's writes are stored in the private device, while reads come from either device - the private one if the requested block is valid in it, the shared one if not. Using this scheme, the majority of data which is unchanged is shared between an arbitrary number of virtual machines, each of which has a much smaller file containing the changes that it has made. With a large number of UMLs booting from a large root filesystem, this leads to a huge disk space saving. It will also help performance, since the host will be able to cache the shared data using a much smaller amount of memory, so UML disk requests will be served from the host's memory rather than its disks. " [Taken from http://user-mode-linux.sourceforge.net/UserModeLinux-HOWTO-7.html] Any ideas? Thanks for your help. ____________________________________________________________________________________ Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
