memory overhead and embedded Samba

[Christopher R. Hertel]

On Mon, Jan 24, 2005 at 01:52:03PM +1100, Andrew Tridgell wrote:
> I've been thinking about possible new applications of Samba4 beyond
> where Samba3 has already been deployed. One possible application is
> for Samba4 to support very low memory configurations, so you can
> create a functional micro-server. The sort of thing I am imagining is
> a tiny embedded Linux box (something like the Linksys WRT54GS wireless
> gateway),

...or the Linksys NLU2, which is Samba 2 on X-Scale on embedded Linux.
(Not sure if there's an MMU...)

> but with a firmware that implements an active directory
> domain controller based on Samba4.

...or stripped down to just file or print servers.  There are a handful of 
embedded CIFS stacks out there, such as the BluePeach implementation we 
saw at the last CIFS conference.

An embedded CIFS stack is one of the several ideas I had in mind when I
started jCIFS.  That's not what it turned out to be, but that's okay...
There was someone who got jCIFS (don't remember if it was ours or
Norbert's) to run on the Tini board 
(http://www.maxim-ic.com/TINIplatform.cfm).

> This could make for a very useful
> little office device. Another application could be a NFS->CIFS
> gateway, allowing you to put a tiny server in place to allow your
> existing NFS servers to server up CIFS.

There are a whole lot of other possibilities here, including a WAFS 
back-end.

> The key to these sorts of applications in low memory overhead. I've
> been measuring the "per client" overhead in Samba4, and it currently
> runs at about 15k per connected client when in -M single mode. That is
> vastly lower than Samba3, so it certainly opens up the possibility of
> making these sorts of micro-servers a reality. With the dynamic
> mangled cache size I mentioned in my last email that per connection
> overhead will drop to about 10k (we have 5k of data sitting around in
> the mangled cache at the moment).
>
> So in a little device like the WRT54GS with 32M of ram you could quite
> happily have several hundred users connected to your server, as long
> the CPU can keep up. The typical load on a domain controller is quite
> low, so I think this will not be a problem.
>
> Does anyone have any other uses for this sort of tiny footprint CIFS
> server?

Lots.  I've been thinking about this kind of thing for a long time...

Chris -)-----

-- 
"Implementing CIFS - the Common Internet FileSystem" ISBN: 013047116X
Samba Team -- http://www.samba.org/     -)-----   Christopher R. Hertel
jCIFS Team -- http://jcifs.samba.org/   -)-----   ubiqx development, uninq.
ubiqx Team -- http://www.ubiqx.org/     -)-----   crh at ubiqx.mn.org
OnLineBook -- http://ubiqx.org/cifs/    -)-----   crh at ubiqx.org