[Samba] Samba 4 Slow Performance

Matthieu Patou
Mon, 05 Aug 2013 06:05:17 -0000

On 07/27/2013 08:20 AM, Kinglok, Fong wrote:
> Dear all,
>
> After using samba 3 for two years, I have just spent totally one week
finishing setting up a samba 4 file system in my working school.  There are
about 200 computers, 80+ staff, 1000 students and 10 printers.  The AD was
properly setup, mandatory profile and one GPO policy (which is printer download
trust) is effective for all users.  Logon script is for mapping four shares and
10 printers from the file server.   Also, I have setup two additional DCs (with
AD replication and DHCP server) for two other subnets in the hope to speed up
the logon process.
>
> The benefits of Samba 4 are clear: more robust file serving (supporting the
windows ACL), speedy printing (with the help of point and printer driver) and
administration of AD through with windows remote admin tool.  However, logon
speed is just far from good.
>
> In the days of Samba 3.6, users can logon the system within 20 seconds,
even with more than 80 users logon in the same time (two classes students login
during computer lesson).  Now, with only one user logging in (who is me), it
takes nearly 60 seconds to do the logon.  I have tried disabling drive and
printer mapping in logon script and applying a registry hack (note 1) shorten
the profile waiting time in windows 7 client side but it makes no difference in
logon speed.
>
> I have taken a look on the document in sambaXP 2013:
>
http://sambaxp.org/fileadmin/user_upload/SambaXP2013-DATA/thu/track1/Matthieu_Patou-Smaller_Faster_Scalier.pdf
>
> and two thread in samba-technical mailing list:
> https://lists.samba.org/archive/samba-technical/2013-January/089755.html
> https://lists.samba.org/archive/samba-technical/2013-May/092332.html
>
> It seems that samba team is doing some great work in spotting the unindexed
search in LDB as one of block in performance.  Certainly, I can wait for the new
version 4.0.X for the boost of performance.  However, I am in deep panic when
lessons are going to be launched on 1st September 2013 here in Hong Kong.  Are
there any patches so that I can a hot / dirty fix?
>
I don't think the problem is in the database in your case, can you do a
tcpdump trace starting just before the client is logging on and stopping
it after the logon (ie the 60 sec or so), see
https://wiki.samba.org/index.php/Capture_Packets on how to the tcpdump
capture.

With this trace we should be able to see where is the delay.
Matthieu.

--
Matthieu Patou
Samba Team