On Tue, May 05, 2009 at 06:49:47PM +0200, Josselin Mouette wrote: > Le mardi 05 mai 2009 à 17:24 +0100, Roger Leigh a écrit : > > That might have been a "traditional" reason for a shared /usr. > > However, the package manager can't cope with this setup since > > you have some components of a package installed locally and > > some remotely for all systems using the "shared" part. It's > > an impossible situation to actually cater for in real life. > > Has anyone ever actually *done* this? > > Of course, you just need to think the image you actually update as a > master image, after which it is replicated by any means necessary (be it > systemimager or NFS).
Sure, but you effectively only have "one" master image. You don't have multiple users of /usr with differing /etc or /var. They are all kept in sync. This kind of makes /usr redundant since it is "sharable" but only among identical systems or else you will run into problems. > As for NFS, I’d use root NFS instead of complicating my life with two > different methods for / and /usr, but I guess some are doing it this > way. On the compute cluster I helped set up for biological modelling, we opted to use Debian Live images on the cluster. It IIRC NFS mounts a read-only cramfs filesystem and uses aufs on top of that. There's just the one big filesystem (plus some site-specific mounts for shared data and a big scratch area all the nodes can access). We certainly saw no point in making just /usr mountable since you need a matching rootfs to accompany it. Regards, Roger -- .''`. Roger Leigh : :' : Debian GNU/Linux http://people.debian.org/~rleigh/ `. `' Printing on GNU/Linux? http://gutenprint.sourceforge.net/ `- GPG Public Key: 0x25BFB848 Please GPG sign your mail. -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
