[Linux-cluster] Re: Meaning of "service"

[Lon Hohberger]

On Sun, 2006-04-23 at 13:04 +0200, Troels Arvin wrote:
> Hello,
> 
> On Sat, 22 Apr 2006 11:13:41 -0400, Eric Kerin wrote:
> >> Should I set this up as
> >> a) one Cluster Service,
> >> b) as three different Cluster Services?
> >> 
> > I have a very similar setup for my cluster.  I recommend option b.
> 
> I ended up doing option a, because I couldn't get the other option
> working, for some strange reason.
> 
> By the way: The manual is rather unclear about the difference between
> _adding_ a resource, and _attaching_ a resource. Can someone explain the
> difference?

It's like making a table leg.  Just because you have a table leg doesn't
mean you have to build a table; you could just have this leg sitting
around doing nothing until you decide to use it later.

Attach enough pieces together and you can make a table.  ;)

Unattached (but present) resources are not started by the cluster.

Creating "global" resources separate from a service was primarily
designed to allow for reuse of resources in some cases.  E.g. GFS file
systems, clients for cluster NFS services: create "Joe's Desktop" as an
NFS client resource, and you can attach it to multiple NFS servers in
the cluster.  All instances get the same export options.


Hmmm... I don't think this plays well in to my table-leg example,
because it's really hard to share table legs between multiple tables
which are in different rooms; I think you'd have to have to introduce a
metaphysical redefinition of the world in order for it to work in which
the table legs have built-in infinite improbability drives, but I think
you get the idea. ;)

-- Lon