--- Christine Caulfield <ccaulfie@xxxxxxxxxx> wrote:
> > DLM lockspace 'data'
> > 5 2f06768 1
> > 5 114d15 1
> > 5 120b13 1
> > 5 5bd1f04 1
> > 3 6a02f8 2
> > 5 cb7604 1
> > 5 ca187b 1
> >
>
> The first two numbers are the lock name. Don't ask
> me what they mean,
> that's a GFS question! (actually, I think inode
> numbers might be
> involved) The last number is the nodeID on which the
> lock is mastered.
Great, thanks again!
> >> That lookup only happens the first time
> >> a resource is used by a node, once the
> >> node knows where the master is,
> >> it does not need to look it up again,
> >> unless it releases all
> >> locks on the resource.
> >>
> >
> > Oh, I see. Just to further clarify, does it means
> if
> > the same lock resource is required again by an
> > application on the node A, the node A will go
> straight
> > to the known node (ie the node B) which holds the
> > master previously, but needs to lookup again if
> the
> > node B has already released the lock resource?
>
> Not quite. A resource is mastered on a node for as
> long as there are
> locks for it. If node A gets the lock (which is
> mastered on node B) then
> it knows always to go do node B until all locks on
> node A are released.
> When that happens the local copy of the resource on
> node A is released
> including the reference to node B. If all the locks
> on node B are
> released (but A still has some) then the resource
> will stay mastered on
> node B and nodes that still have locks on that
> resource will know where
> to find it without a directory lookup.
>
Aha, I think I missed another important concept -- a
local copy of lock resources. I did not realise the
existence of the local copy of lock resources. Which
file should I check to figure out how many local
copies a node has and what the local copies are?
Many thanks again, you have been very helpful.
Jas
____________________________________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
--
Linux-cluster mailing list
Linux-cluster@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/linux-cluster
