Samba 4 Slow Performance

Kinglok, Fong busywater at
Tue Jul 30 20:07:42 MDT 2013

On 29 Jul, 2013, at 1:13 PM, Andrew Bartlett <abartlet at> wrote:

> 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:
>> and two thread in samba-technical mailing list:
>> 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
> Authentication Developer, Samba Team 
> Samba Developer, Catalyst IT         

Thank you all for responding.

In these days, I am trying hard to understand the reason of the delay in logon.

Following your advice, I've done some test on
1. Profile deploying
2. GPO

For the first one, I try using roaming profile for one testing user, it turns out 7 seconds to logon the system.  It seems that the culprit of the delay is in the my old mandatory profile.
For the second one, I try disable all GPO (I only enable point and printer driver trust and folder redirection), turning it on / off does not change the logon time significantly.

So, I try digging into how to create mandatory profile properly once again.  Here I found:

By following the link's instruction, I found it needs 20 seconds in logon.  I hope I can further decrease the logon time (anyone got a hint?)

I will keep updating the list if I found something worth sharing.


Kinglok, Fong

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