[Samba] Samba 3.0.22 - slow performance - Really urgent help

[Alan Pek]

Hi Volker,

Thanks for the useful feedback.

a) Though the CPU utilisation is not high but there memory used and 
swapped are very high. This will slow it down further.

b) Think every samba connection will consume a considerable amout of 
memory as well. 

c) We did a test, by saving a huge number of files onto local drive (on 
enduser PC) and the copy into the mapped drives This is much faster, 
probably by factor 6 or more, then using Excel marco
and writing directly into the samba share over NFS. 

d) Looking at the system, and samba processes,  how should I do a truss 
with high-resolution timestamps on the smbd processes ? Every smbd process 
?
Just do :

        truss -p 20995 without any option ?

  apps 28824 14805   1 13:50:58 ?          34:40 /opt/DBsamba/sbin/smbd -D
    root 14808 14807   0   Mar 27 ?           0:00 
/opt/DBsamba/sbin/winbindd
    root 23698 23434   0 18:13:59 pts/3       0:00 grep -i mb
    root 21729 14805   0 18:01:18 ?           0:01 /opt/DBsamba/sbin/smbd 
-D
    root 29259 14805   0 11:32:38 ?           2:07 /opt/DBsamba/sbin/smbd 
-D
    root 14809 14805   0   Mar 27 ?           0:00 /opt/DBsamba/sbin/smbd 
-D
    root 20629 14807   0   Mar 29 ?           0:00 
/opt/DBsamba/sbin/winbindd
    root 14807 21996   0   Mar 27 ?           0:01 
/opt/DBsamba/sbin/winbindd
  apps 27073 14805   0 17:18:58 ?           0:04 /opt/DBsamba/sbin/smbd -D
    root 11568 14805   0   Mar 29 ?          76:51 /opt/DBsamba/sbin/smbd 
-D
    root 14801 21996   0   Mar 27 ?           0:06 /opt/DBsamba/sbin/nmbd 
-D
    root 22898 14805   0 18:09:42 ?           0:00 /opt/DBsamba/sbin/smbd 
-D
    root 14805 21996   0   Mar 27 ?           0:02 /opt/DBsamba/sbin/smbd 
-D
    root 11509 14805   0   Mar 29 ?          77:25 /opt/DBsamba/sbin/smbd 
-D
    root 29253 14805   0 11:32:25 ?           1:37 /opt/DBsamba/sbin/smbd 
-D
    root 23144 14805   0 18:10:55 ?           0:00 /opt/DBsamba/sbin/smbd 
-D
  apps 20995 14805   0 17:56:25 ?           0:04 /opt/DBsamba/sbin/smbd -D
  apps  3805 14805   0 14:26:03 ?           0:15 /opt/DBsamba/sbin/smbd -D

e)  Network tracing , meaning application profiling by putting a sniffer, 
or/and snoop on both samba and nfs side ?

Thanks again.

Regards
Alan




Volker.Lendecke at SerNet.DE 
04/01/2010 05:48 PM
Please respond to
Volker.Lendecke at SerNet.DE


To
Alan Pek/db/dbcom at DBAPAC
cc
samba at lists.samba.org
Subject
Re: [Samba] Samba 3.0.22 - slow performance - Really urgent help






On Thu, Apr 01, 2010 at 05:24:26PM +0800, Alan Pek wrote:
> Have been struggling with this for the past 10 days, we are running 
Samba 
> 3.0.22 on VCS zone, we have end users saving files
> onto Samba mapped drive, and complained that it 5mins to save 300 files, 

> now it takes 30 mins.  There is recently a change in the
> topology.
> 
> Before
> 
>         Enduser ----------- samba mapped -------------- server (local 
> attached storage)
>                                                       physical
>                                                       Solaris 8
> Now
> 
>         Enduser-------------samba mapped ------------  server 
> ------------------------------ SFCFS/HA
>                                                      virtual VCS NFS 
> cluster
>                                                      Solaris 10 
> 
> 
>         We have reverted the NFS from version 4 to 3
> 
>         Fine tune Samba, wb and rb are at 64k
> 
>         Is there in samba log somewhere to tell me why is the bottleneck 
?
> 
>         If I move the Samba server which is less loaded in Memory 
> consumption , will it help.
>         Is the above degrading expected ?

Some slow-down is expected if you re-export NFS because the
data will travel over the network twice instead of once. A
factor of 6 is a bit more than is expected though. To see
where the bottleneck is, it might be interesting to look at
simultaneous network traces for the SMB and NFS side of your
Samba server to see what NFS requests are triggered by what
SMB requests. Doing a truss with high-resolution timestamps
on the smbd processes might also give hints. Next would be
to look at "top" (pstat?) if there is a local CPU bottleneck
on the Samba server. There's just many things that can go
slow, and in a moderatly complex environment (HA clusters
fall into this category), this can be an interesting hunt
:-)

Volker
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