On Tue, 09 May 2006 14:02:51 -0400 Fareha Shafique <[EMAIL PROTECTED]> wrote:
> Fareha Shafique wrote: > > > Corey Wright wrote: > > > >> storage space is conserved because files only exist in one place, but > >> are > >> referenced within multiple vservers though special hard links. > >> > >> memory space is conserved because binaries and shared libraries (and > >> any item in the file cache, i suppose) only exist in memory once, > >> though many > >> vservers may be executing/using the file. the idea is to extend the > >> concept of "shared libraries" to vservers, so that just as a > >> shared library may be referenced by multiple applications and it only > >> exists in memory once, the same is true for a shared library > >> referenced by > >> multiple vservers (by way of vhashify). > >> > >> all the examples i have seen enable vhashify for vserver guests, not > >> the host. i presume it is possible, but it is never applicable in my > >> case because hard links are only shared on a single filesystem (where > >> i mount my > >> host's executables/libraries on /usr and my vservers on /home). > >> > >> hth. > >> > >> corey > >> > >> > > Thanks, that explaination helps :) > > Now, is it only libraries and binaries that can be shared or can a > > vserver be an exact replica of the host. > > Oh sorry, that was already answered. I guess anything on the filesystem > can be shared. let me again emphasize: i have never seen vhashify used to "unify" the host with guests. i don't know if the vhashify application allows for such. you might be able to do it by creating a skeleton configuration in /etc/vservers representing the host (ie /etc/vservers/host) with a vdir that symlinks to /. just be sure to exclude /etc/vservers or you may experience recursive problems. but that's a total hack, unsupported, and may even void the warranty. ;-) > > How about if I want the filesystem of vserver vs1 to be an exact > > replica of the host, and only when I write/modify any file a local > > copy should be created for vs1 (using COW)? Is this possible? > > Let me explain this better. Say I want to upgrade some software or > install new software on my host machine. Before doing this, I would like > to test the upgrade in an environment that is an exact replica of the > host machine. Is it possible to create a vserver identical to the host > so that it can be used as the test environment? why don't you instead have two vservers: one test & one production. push all your production applications/configuration from the host into a "test" guest. when the "test" guest works how you want, just copy the "test" guest to the "production" guest and unify the two. i do something similar. i have a "test" guest (that's literally the name of the guest) where i test applications and when everything works like i want, i "apt-get install" or copy the tested application on a "production" guest, copy over the configuration, vhashify the "production" guest, and start it. the added benefit of having your "production" environment contained within a guest is that to relocate the production environment you simply stop the guest, tarball/cpio/rsync/scp/etc it (the guest and its configuration) to another vserver host, and start it there. i think you are trying to push a square peg into a round hole with your current design and should reconsider if possible. corey -- [EMAIL PROTECTED] _______________________________________________ Vserver mailing list Vserver@list.linux-vserver.org http://list.linux-vserver.org/mailman/listinfo/vserver
