Subject: hello

From: [email-masked] (David Kotz)
Date: Mon, 29 Jun 92 11:54:43 -0400

I just joined the HPFF IO group. I am interested in multiprocessor
file systems, and in particular the operating systems issues
underlying such file systems. But I am also interested in the file
system interface (see my Usenix file systems workshop paper); hence my
interest in this group. Up front, I must say that I am more interested
in the general question of multiprocessor file systems and their
interfaces than in Fortran or HPF directly.

Is there a place where I can quickly read up on the Fortran 90 I/O
interface semantics, which seems to be where we're starting?

Is there any form of I/O proposal for HPF yet?

It appears that people are reluctant to include any new I/O
constructs.  I personally think that the OS can do a lot for parallel
I/O, but I think that trying to write a parallel program to use
parallel I/O using only old-fashioned sequential I/O constructs is
silly. This is why HPF and Fortran 90 are/were created -- to allow
people to express parallelism directly.

If you're interested in what some vendors are doing with OS support
for parallel I/O, including some of the issues already discussed in
this group, see the papers about the new nCUBE file system (Del
Rosario, DeBenedictus, and others). Neat stuff. 

The question about the format of files is an interesting one. A
parallel computer that stores its files in some funny format may have
high performance locally, but not be able to make the file system or
files remotely accessible via, say, NFS. Look at the CM-2 for example.
In this increasingly networked world, this is bad.

I'll have to reread the archives again; there are more comments I'd
like to make.

David Kotz
Asst Prof
Math & CS
Dartmouth College
[email-masked]