[Samba] Samba performance issues

[Robert Stuart]

Hi,

I'm rather interested in the outcome of this on or off the list; but I
suspect there will be other people on the list who are interested -
please keep posting to the list :-)

I think we have very similar HW.  We have a dual CPU (1.4G PIII) LPr2000
netserver with 10k and 15k drives.  We normally sit around < 5% cpu so
it seems to be something about your config, probably not your HW.  Our
box also does internal http, mail, dns, fax, lpd, ldap etc.

Can I suggest you run top and see what seems to be using CPU time?  Does
%CPU in the process list include sys time?  I think it does, if so, it
will help you get an idea of what is contributing to the 60% sys time
(even if top doesn't include sys then it is likely to be showing
culprits anyhow).  Do you run anything else on this machine (eg
oracle)?  :-)  Perhaps posting  ps axf and a copy of a top page might
help.

Your LDAP backend... is it getting busy?  Are the relevant things
indexed?

I'd upgrade your kernel to the last RH7.3 errata (2.4.18-10?).

You will likely get locking issues (discussed on samba-technical show
stopper) if you are using ldap sam, I patched the samba 2.2.5 rawhide
rpm.  I'll send that in a separate email to you.

Good luck.

Martin MOKREJ© wrote:
> 
> On 24 Sep 2002, Bradley W. Langhorst wrote:
> 
> > On Tue, 2002-09-24 at 18:07, Martin MOKREJ© wrote:
> > > On 24 Sep 2002, Bradley W. Langhorst wrote:
> > >
> > > > probably you want to run the iostat 1 during heavier load...
> > > > however the summary result does look funny to me...
> > > >
> > > > On my system we have ~ 1:1 ratio of reads to writes
> > > > you have a ~ 1:200 ratio of reads to writes.
> > > > Does that make sense in your environment?
> > >
> > > Didn't you have a look into the first lines where's the summary output
> > > from iostat?
> > >
> > sure i did... maybe i'm misreading it
> > avg-cpu:  %user   %nice    %sys   %idle
> >           16.79    0.00   26.39   56.82
> >
> > Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
> > dev8-0           11.80         2.24       184.95     541354   44609586
> > dev8-1           11.80         1.67       184.95     403090   44609586
> >
> > Unless I'm mistaken the summary says that (on average) he only has 2
> > reads/s vs 185 writes/s
> 
> You are right, sure. But my point was why is the *current* load that high.
> That's why I had a look on statistics per every second.
> 
> >
> > > All those other remaining output lines show zero disk
> > > activity ...
> > That's why I suggested he run iostat when the system is under more load.
> 
> In principal I agree anyway. ;)
> 
> >
> >
> > > >
> > > > It doesn't look like your system has a memory problem so i'd not worry
> > > > about vmstat.
> > >
> > > I'd would worry. Actually, what says "dmesg" command?
> > The reason I think memory is no problem here is:
> > Mem:  3229040K av, 3166372K used,   62668K free,       0K shrd,  148480K
> > buff
> > Swap:  513976K av,       0K used,  513976K free                 2758060K
> > cached
> >
> > so the swap file has not been touched and there is 2.7gig of disk being
> > cached in RAM
> 
> Yes, but the "sy" column in the output of vmstat was quite high. That
> worries me. ;)
> 
> I think we should not Cc: the samba email list to these emails anymore. ;)
> --
> Martin Mokrejs <mmokrejs at natur.cuni.cz>, <m.mokrejs at gsf.de>
> PGP5.0i key is at http://www.natur.cuni.cz/~mmokrejs
> MIPS / Institute for Bioinformatics <http://mips.gsf.de>
> GSF - National Research Center for Environment and Health
> Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany
> tel.: +49-89-3187 3683 , fax: +49-89-3187 3585
> 
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-- 
Robert Stuart
Systems Administrator
Ph: 61 7 3864 0364
Fax: 61 7 3221 2553