Coda File System

Re: Q: Is Partial Replication Possible?

From: Brian White <>
Date: Wed, 26 Feb 2003 14:28:47 -0500
> > > >Let's say I have a system with 100 servers, each serving up files from a
> > > >large not-heavily-used archive to a local cluster of machines.  I have
> > > >these servers in place already for other purposes; using CODA to make
> > > >the archive available is just one more benefit.
> > >
> > > CODA does not serve data from other file systems.  Data in a CODA
> > > server must be stored in CODA via coda.  NFS can export an existing
> > > file system.  CODA can not do this.
> >
> > I know what you're saying and I understand.  I was thinking of a "volume"
> > as a filesystem that is "served" by the various servers to all of the
> > clients.  The volume I was referring to was for this example the "large
> > not-heavily-used archive".
> But I think, if I understand what you want to do, you can make each of
> those "servers" be Coda *clients*, and have them serve out to their
> local clients via NFS or HTTP.  Would that meet your needs?

I thought about this...  It meets the needs in that it allows each of the
subnet servers to provide the fast file response while keeping multiple
copies across a few back-room servers.  The goal it doesn't meet is the
scaleability aspect.  If I've got these 100 servers sitting around caching
files, then really they're wasting a lot of disk space.

There are lots of ways I could set up our servers here (which is nowhere
close to the size I'm using in my example, but I like to plan ahead :-) and,
being somewhat of an optimizer and perfectionist, am trying to find the
best possible choice for both speed and capacity.

> There have been, of course, a number of research projects on similar
> things (see Darrell Long's Swift, TicketTAIP, and CHEOPS, to name just
> three).  AFAIK, none of that has been integrated with Coda.  Would make
> an interesting project.

It would.  It's actually one I started some serious thinking about at one
point, but the reality is that I don't have the time or the knowledge of
the linux kernel to actually undertake a project like that.

                                 ( )

            On the road to success, you can be sure of one thing...
                   there is never a crowd on the extra mile.
Received on 2003-02-26 14:30:24