Re: VFS ROADMAP (and vfs01.patch stage 1 available for testing)

[Rahul Siddharthan <rsidd@xxxxxxxxx>]

Matthew Dillon wrote:
>    And, finally, once all of that is done, around stage 75, we may even be
>    able to rip out the per-vnode locks that UFS uses and replace them with
>    fine-grained data block range locks, which will allow massive parallelism
>    even operating on a single file.
>
>    This is a pretty ambitious plan, it could take me into next year to
>    finish it all but when it is done we will be extremely well positioned
>    for the ultimate goal of implementing fully transparent clustering.

Sorry if these questions are naive.  I've been meaning to ask: what
are the goals of this "transparent clustering" idea?

I've been reading a bit about the linux OpenSSI project.  There,
apparently, you have a shared filesystem and a shared process table,
so you can access processes on other computers, migrate jobs from a
heavily-loaded node to a less-loaded node, and so on.  Is that the
idea for DragonFly too?

What about threads?  Will a multi-threaded program on a future
DragonFly cluster run as if it were on a multi-CPU SMP machine, or
will it stay on one node (which, as far as I can make out, is the case
with Linux OpenSSI)? 

I ask because I do a bit of scientific programming.  I haven't done
any parallel/clustered programming so far, but may want to in the
future.  The "standard" way to do it is to build a (usually linux)
cluster and use MPI or similar special-purpose libraries for
message-passing.  I'm wondering whether in the long-term picture for
DragonFly, this will be somehow simplified/improved, or does this have
nothing to do with DragonFly's goals...

Rahul