Samba scalability?

[Shawn Wright]

On 21 Dec 2000, at 7:51, Matthew Geddes wrote:

> > Currently our two NT4 server carrying the heaviest file sharing load
> > deal with about 150 concurrent user connections, and will see 600-
> > 1200 file locks during normal use. Most of this is user home
> > shares, with some shared network apps thrown in; clients are 90%
> > NT4 WKS, with some student win9x PCs and laptops.
> 
> We've had over 300 concurrent connections. We're doing the whole lot on
> a Linux box with Samba 2.0.7. The box itself is a 450MHz Celery
> processor and 256MB RAM. The HDD is a single 13GB IDE. It sometimes uses
> a fair amount of swap, but we've not had any complaints. This box also
> manages a connection from each machine to it's closest printer. This box
> is not a PDC or WINS server.

Hmmm. Is there a formula for calculating Samba's memory 
requirements based on connection #s, volume sizes, etc? Most of 
our servers are in the 40 - 60Gb range for disk storage.
 
> > One more big question: I'm not tied to Linux by any means, as I've
> > used various BSDs over the years, so I'd by interested to know if
> > there is a particular advantage to running samba over a certain
> > platform, OpenBSD, FreeBSD, etc?
> 
> I think most of these are fine. I've never tried BSD under a big load,
> but Samba certainly runs on it ;-)

The main reason I ask is security - although our two longest 
running linux boxes (3.5 and 5.5 years) have been very stable, 
we have had two remote exploits during this time (both on 
RedHat 6.2). To be fair, both could have been avoided had I 
been more diligent on the patches, but it also makes me wonder 
if going with OpenBSD wouldn't be a better idea - at times I find 
the volume of patches from RedHat to rival M$, and I don't 
always have time to investigate patches right away.

Getting back to Samba - are there others out there who have 
made the move from NT Server to Samba in a school 
environment? A few issues that I'm a bit worried about:

1. Lack of ACL support (I know there talk of this with TNG, but it 
sounds a bit too experimental for me right now). We often have 
cases where user shares on NT will have several users and 
groups listed in the ACL, with varying permissions for each (ie: 
we allow some teachers access to some students' home shares, 
web shares, etc). It would seem that some very careful planning 
is needed to make this work correctly within the *nix file 
permissions model.

2. Quota support - I've searched the list archives, and seen a few 
questions about quota support, but not too many answers. How 
many are using quotas with NT/Win9x clients, and how well does 
it work? Are there tools to expand upon the disk full message, 
and perhaps send a popup message to the client explaining why 
they can't save a file? Reporting tools for informing admins of 
who's over quota?

3. Backups - We currently use BackupExec 6.5 on an NT server 
to backup all servers. Are there any issues relating to backups 
using samba?

ps: I'm not too worried about NT PDC/BDC issues - we will keep 
at least two NT servers to support specific software that requires 
it. For now, I need samba/linux to emulate an NT member server 
as closely as possible...


========================
Shawn Wright
Computer Systems Manager
Shawnigan Lake School
http://www.sls.bc.ca
swright at sls.bc.ca