[Samba] SMB hogs cpu - printing freezes server

[jra at dp.samba.org]

On Fri, Jun 13, 2003 at 12:35:28PM +1000, Craig Silva wrote:
> We have 2.2.7a running on redhat 9.0  with 256 MB ram. Dual cpus - but
> only PII 300's.  Its not running as a PDC - the PDC is an nt box.
> 
> The system is set up as our main print server with 60 odd print queues
> that service a wide variety of printers. Approx 200 odd windows pc's as
> clients. The print files themselves can be largish with multi-page docs
> with lots of graphics.
> 
> What we are finding is that under certain circumstances (which appears
> to be a number of big print jobs hitting the server and or users
> browsing their printers) the smbd processes clog up the cpu - we were
> running top and vmstat to try to get a handle on what happens when it
> freezes. These processes start to take an increasing percentage of both
> cpu and memory with the root owned smbd process topping out at a
> reported 99% the last time the system froze. These processes hang about
> in top - they don't drop out as is the case when the system is running
> correctly

This is the problem that we fixed in 3.0 by re-designing the printer
job query code to be (mostly) asynchronous. The branch APPLIANCE_HEAD
contains these fixes in a 2.2.x codebase.

I'd recommend trying out the beta version of 3.0 to see if this fixes the
problem.

Jeremy