[Samba] Re: Severe problem with Samba

[Martin Rootes]

Jeremy,

	further to this e-mail, last wednesday evening (30/01/02) we moved the Samba service to a 
more powerful machine (a dual 750MHz processor V880, running Solaris 2.8), running the 2.2.3-
CVS version that I'd downloaded around the 18/12/01. At first everything seemed OK and was 
running smoothly, however this was during an 'inter semester gap', and so not much real work 
was going on. Then on Monday (04/02/02), when the students started work again all hell broke 
loose. We were seeing the same symptoms as previously described but happening far more 
often . I had to stop and restart Samba about 4 or 5 times to clear the processes out, after re-
starting the service would be OK for about half an hour and then we'd start getting the build up 
again. I attempted various configuration changes, removing quota support, removing strict 
locking (not sure why that was set anyway), setting keepalives to 30, all to no avail. Eventually I 
compiled and re-installed an old version of Samba (2.0.7) that we had been using successfully in 
the past and started up the service using this. Since then we have not had any problems, 
yesterday the number of connections peaked at about 1140, the load on the server being a very 
respectable 0.4. 

	I noticed on the Samba pages that version 2.2.3 has now been officially released, has there 
been any changes to this version since December 18? Is there a known problem with any of the 
versions post 2.0.7 that might explain these symptoms? Is it simply that each version requires 
more resources and so increases load on the system to a point that normal operation breaks 
down? Whilst I can run the system on the old version of Samba, I'd prefer to use a later version 
as I believe quota support (which ideally we need) was only 'experimental' in 2.0.7. Are they any 
crucial things we should be looking at?

	Finally, I've just noticed today that you'll actually be in Sheffield on the 21/02/02 for a Linux 
seminar at Hilsborough and then later this very establishment! I would really appreciate it if we 
could get together for a chat about the problems we are experiencing, would it be possible to get 
an hour or so of your time on that day?

	Martin.

===========================================================
Martin Rootes - Senior Systems Programmer/Analyst, Sheffield Hallam University
Email :         M.J.Rootes at shu.ac.uk                      Phone: 0114 225 3828
===========================================================

> Thanks Jeremy, I'll compile it up and test it out.
> 
> 	Martin.
> 
> Date sent:      	Thu, 13 Dec 2001 15:17:32 -0800
> To:             	Martin Rootes <M.J.Rootes at shu.ac.uk>
> Copies to:      	Samba <Samba at lists.samba.org>
> Subject:        	Re: Severe problem with Samba
> From:           	jra at samba.org (Jeremy Allison)
> 
> > On Thu, Dec 13, 2001 at 06:08:03PM +0000, Martin Rootes wrote:
> > > Dear All,
> > > 
> > > 	we are experiencing severe problems with Samba 2.2.0 (with quota support) running on a 
> > > dual processor (400MHz) Sun E450 running Solaris 2.7. This is used as a central file server for 
> > > student diskspace, accessed by approx 1200 PCs running NT 4. Up until recently we 
> > > experienced some, what we assume to be, loading issues with connections during the middle of 
> > > the day being slow. However, recently we have been encountering severe problems. Everything 
> > > seems fine until  midday, then what we start to see is the number of smbd processes going up 
> > > whilst the number of connections (determined from smbstatus -b) dropping, students with 
> > > connections starting getting slow responses and no new connections are being made, load on 
> > > the system skyrockets. stopping samba and restarting seems to cure the problem, but the 
> > > problem can re-occur. We are in a desperate panic at the moment as the students are all doing 
> > > assignments and this is seriously affecting their work. We have tried various tweaks to Samba 
> > > (deadtime, change notify timeout), the tcp stack and have tripled system memory, all to no avail. 
> > > We also seem to have an issue with keepalives and tcp_nodelay, neither of which seem to work 
> > > at all, we see the following messages in the log about keepalives:-
> > 
> > We think we've solved these in the latest Samba 2.2.x CVS tree. Unfortunately
> > this isn't released as "stable" 2.2.3 code yet (getting close though). If you'd
> > like to test this the CVS branch is SAMBA_2_2. It has been confirmed to fix this
> > problem on other Solaris and HPUX boxes.
> > 
> > Jeremy.
> 
> 
> ------------------------------------------------------------------------------
> Martin Rootes - Senior Systems Programmer/Analyst, Sheffield Hallam University
> Email :         M.J.Rootes at shu.ac.uk                      Phone: 0114 225 3828
> ------------------------------------------------------------------------------
> 
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Martin Rootes - Senior Systems Programmer/Analyst, Sheffield Hallam University
Email :         M.J.Rootes at shu.ac.uk                      Phone: 0114 225 3828
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