Re: [PATCH 1b/7] dlm: core locking

Lars Marowsky-Bree
2005-04-28T16:46:19Z

On 2005-04-28T09:39:22, Daniel McNeil <daniel@osdl.org> wrote:

> Since a DLM is a distributed lock manager, its usage is entirely for
> locking some shared resource (might not be storage, might be shared
> state, shared data, etc). If the DLM can grant a lock, but not
> guarantee that other nodes (including the ones that have been kicked
> out of the cluster membership) do not have a conflicting DLM lock, then
> any applications that depend on the DLM for protection/coordination
> be in trouble. Doesn't the GFS code depend on the DLM not being
> recovered until after fencing of dead nodes?

It makes a whole lot of sense to combine a DLM with (appropriate)
fencing so that the shared resources are protected. I understood David's
comment to rather imply that fencing is assumed to happen outside the
DLM's world in a different component; ie more of a comment on sane
modularization instead of sane real-world configuration.

Sincerely,
Lars Marowsky-Brée <lmb@suse.de>

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