[comp.os.mach] References/Info on NFS ports to mach

smiller@umn-cs.CS.UMN.EDU (Steven M. Miller) (11/18/89)

Is there any reports/papers/etc out there on what was done to port
NFS to Mach?   It would seem that with Mach's VM scheme file sharing
between multiple machines (particulary multiple mach machines) could
prove to be a file consistency nightmare.

Thanks in advance,

-Steve
-- 



			-Steven M. Miller, U of MN

zs01+@andrew.cmu.edu (Zalman Stern) (11/21/89)

I'm not a Mach expert, but so far as I know, the NFS port to Mach was
mostly putting vnode support in the kernel. I believe that the vnode hooks
already support mmap so there shouldn't be too much magic involved.

The only distributed virtual memory facilities I know of on Mach are
implemented using external pagers and therefore would not involve the NFS
code at all. The external pager is responsible for implementing the
consistency protocol among machines. (The kernel will maintain consistency
within a single machine, which may be a tightly coupled multi-processor.)
If one wants to use an NFS partition as backing store for the external
pager, that shouldn't be a problem since it will only happen on a single
machine. If another machine wants data that has been paged onto the NFS
partition, it has to go through the external pager protocol rather than
NFS.

Sincerely,
Zalman Stern
Internet: zs01+@andrew.cmu.edu     Usenet: I'm soooo confused...
Information Technology Center, Carnegie Mellon, Pittsburgh, PA 15213-3890

floyd@smoke.BRL.MIL (Floyd C. Wofford) (11/21/89)

In article <17098@umn-cs.CS.UMN.EDU> smiller@umn-cs.cs.umn.edu (Steven M. Miller) writes:
>Is there any reports/papers/etc out there on what was done to port
>NFS to Mach?
>
>-Steve

I know of no reports, but BBN has a machine which runs both Mach and NFS.
The generic name is Butterfly.

george@jones.cis.ohio-state.edu (George M. Jones) (11/21/89)

In article <11658@smoke.BRL.MIL> floyd@smoke.BRL.MIL (Floyd C. Wofford) writes:

   In article <17098@umn-cs.CS.UMN.EDU> smiller@umn-cs.cs.umn.edu (Steven M. Miller) writes:
   >Is there any reports/papers/etc out there on what was done to port
   >NFS to Mach?
   >
   >-Steve

   I know of no reports, but BBN has a machine which runs both Mach and NFS.
                                                     ^^^^      ^^^^
   The generic name is Butterfly.

Sort of.  From what I understand they took a very early release from
CMU (release 0 ?) and have pretty much done their own thing with it
ever since, not tracking CMU changes.  As of the next release they are
dropping support for tasks and ports, and never had threads (C-threads
anyhow) and are changing the name to nX.

Depending on on your interests though you might want to get in touch
with them.  They have done extensive work with the memory managment
code (has anyone else tried to put a Unix-like OS on a NUMA machine ?)
and did their own NFS port.  For starters you can try reaching them
at bf-questions@bbn.com...which I think is intended largly for
customer support, but I don't think they will be TOO annoyed at a
request for information.  I could be wrong :-)

---George Jones

-=-
OSU Computer & Inf. Science 2036 Neil Ave.,Columbus,Ohio 43210. 614-292-7325
george@cis.ohio-state.edu or ...!osu-cis!george
"When goods don't cross borders, armies will"
---Frederic Bastiat

bolosky@cs.rochester.edu (Bill Bolosky) (11/22/89)

>code (has anyone else tried to put a Unix-like OS on a NUMA machine ?)

I know of three examples: Alan Cox and Rob Fowler's PLATINUM kernel implements
a Mach-like VM system on the Butterfly from which one could build a Unix-like 
system if one were so inclined; the Psyche group here at Rochester also has
a kernel which could potentially support unix-like operations; and Bob 
Fitzgerald, Dan Poff and I ported Mach to a NUMA machine called the IBM 
ACE Multiprocessor Workstation.  PLATINUM and the ACE Mach effort are
described in "The Implementation of a Coherent Memory Abstraction on a
NUMA Multiprocessor: Experiences with PLATINUM" and "Simple But Effective
Techniques for NUMA Memory Management," respectively, both of which will be
presented at ACM SIGOPS SOSP in December.


>---George Jones
>
>-=-
>OSU Computer & Inf. Science 2036 Neil Ave.,Columbus,Ohio 43210. 614-292-7325
>george@cis.ohio-state.edu or ...!osu-cis!george
>"When goods don't cross borders, armies will"
>---Frederic Bastiat


Bill Bolosky
bolosky@cs.rochester.edu