[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: deprecating /usr as a standalone filesystem?

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.


  .''`.  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.

Reply to: