[Samba] smbd high cpu load

[Jeremy Allison]

On Wed, Oct 22, 2008 at 03:27:10PM -0700, Wayne Cochran wrote:
> We have a Linux file server for a set of computer science and  
> engineering
> labs where each lab contains machines running Mac OS X, Ubuntu Linux,
> or some incarnation of Windows. At times the these machines become
> almost unusable and I think I have narrowed the problem to smbd  
> processes
> soaking up all the CPU on the server. Running 'top' on the server
> reveals a dozen or so entries like the following:
>
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 18229 millerbr  20   0 12420 3980 2992 R   26  0.1   0:03.85 smbd
> 18225 tande8    20   0 12380 3564 2660 S   22  0.1   1:00.19 smbd
> 18861 dhenniga  20   0 12676 4316 3328 R    7  0.1   0:01.86 smbd
> 18210 samcprui  20   0 12616 4064 3128 S    3  0.1   0:55.84 smbd
> 18214 mlhorn    20   0 12568 3912 3060 S    3  0.1   0:25.23 smbd
> 18867 tsze      20   0 12784 4656 3592 S    3  0.1   0:10.28 smbd
> 18728 daflores  20   0 12684 4560 3516 S    2  0.1   0:35.44 smbd
> 18678 twharris  20   0 12780 4556 3552 S    1  0.1   0:11.35 smbd
> ...
>
> Looking through the log files reveals nothing obvious at first glance,  
> but of course
> I am not sure what to look for and there are a lot of log files.
>
> What steps should I first take to debug the situation?

What version of Samba are you running on this server ?
What is the operating system on the server ?

What does tracing the smbd execution with strace, or
ptrace say when smbd is spinning like this ?

Jeremy.