Large scale Samba installations

[acherry at pobox.com]

Hello Samba folks-

I'm currently in the position of trying to convince my IT management
that using Samba to provide SMB services to our NT client base is a
Good Thing.  Our client/server situation is as follows:

     o An HA cluster of two quad-cpu (400MHz) Sun Enterprise servers,
       with IP address takeover on failover.
     o About 1000 Windows NT clients connecting via SMB
     o About 250 Solaris/SPARC clients connecting via NFS

We're currently using a commerical product (which I will be kind
enough not to name) which is proving to not scale well at all.  This
has less to do with the capabilities of our servers and network, and
more to do with some serious design flaws in the product.  As a
result, I'm getting very close to convincing my superiors that Samba
is the way to go, despite being an "unsupported freeware" product.
At this point, the main concern is that we have only used Samba on a
smaller scale, so we don't have direct evidence that it will fare
any better once we scale it up to the level mentioned above.

I'm pretty sure I can make Samba work in a symmetric failover
situation by running two separate instances of Samba and bind only to
the appropriate interface in each (the cluster does IP address
takevoer in the event of a failover).  My guess is that this is what
HP does in their packaging of Samba for their HA servers.  This would
be a major selling point for Samba, since the commercial product can't 
do this (i.e. half of our cluster is basically sitting idle)... though
of course they promise that it will be "supported in the next release"
;-)

So, I'm looking for examples of successful Samba installations on this
scale (or larger!).  If anyone on this list has administered such an
installation, I'd GREATLY appreciate it if you could provide some input
regarding both the positives and the negatives you've encountered in
your installation.

I'd be especially interested in sites that use Samba on Solaris/SPARC
servers, doubly so for HA environments.  But other platforms would be
of interest also -- I'm mostly interested in the scalability of Samba
itself.

Thanks!

-Andrew