[Samba] Ideas for distributed Samba servers

[Adam Tauno Williams]

On Sat, 2010-04-10 at 10:14 -0700, Eric Shubert wrote:
> Robert LeBlanc wrote:
> > I'm trying to think about how to setup a Samba system and would like to pick
> > the brains of some experts. We are looking up put a large amount of storage
> > ~75TB in a central data center. We have some remote (ok, not remote, but
> > across slower links, ok if you consider several hundred clients over 1Gb to
> > be slow) locations that we would like to set up samba servers that 'cache'
> > the file system and serve it up to the clients in the building and sync with
> > the main data center storage.

a.) I don't think you can really do that with a 'file server'

b.) I believe what you describe is almost exactly how AFS works.
<http://www.openafs.org/>
  "OpenAFS is the world's foremost location independent file system."

c.) Most SAN vendors provide a block-level replication solution for
their products.

>  The idea is have a couple of TB that are
> > located in the building that serve up the Samba share. When a client
> > requests a file, if it's in the local cache it is served up from there, if
> > not then the Samba server grabs the file from the main data center and
> > serves it to the client. When a file is written, something like rsync is
> > used to transfer only difference back to the main data center. The problem
> > is that I'm not sure of a file system that does this. We are using Lustre on
> > our HPC, but this won't do what we want.

With all the fun of file locking, concurrent access, etc... I think what
you describe just won't work, or at least will never work well.  Why not
just you a groupware server that supports document check-out and
check-in;  that seems like the correct solution to me.   Or possibly
something like iFolder <http://ifolder.com/ifolder>