[Samba] Samba 4 Slow Performance

Andrew Bartlett
Mon, 29 Jul 2013 05:13:49 -0000

On Sat, 2013-07-27 at 23:20 +0800, 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.

It is one block, but it is the one we expect to really hit at around
10000, not 1000-2000.  As Richard has indicated, what we need from you
is an indication of what operation is slow.  Timeouts of this order
indicate something different to a slow database - they indicate things
like DNS timeing out.

Once you work out which specific operation is blocking, we can
investigate more - be it in regards to your network, or our code, we
don't mind either way, but we need to work out which to look into.

Andrew Bartlett

--
Andrew Bartlett
http://samba.org/~abartlet/
Authentication Developer, Samba Team           http://samba.org
Samba Developer, Catalyst IT                   http://catalyst.net.nz