facing very slow authentication responses from samba4, urget help needed

Andreas Oster aoster at novanetwork.de
Sat May 12 00:42:37 MDT 2012

Am 11.05.2012 15:34, schrieb Andrew Bartlett:
> On Fri, 2012-05-11 at 11:57 +0200, Andreas Oster wrote:
>> Am 11.05.2012 10:43, schrieb Matthieu Patou:
>>> On 05/10/2012 11:41 PM, Andreas Oster wrote:
>>>> Hello list,
>>>> I have migrated our Windows AD to a samba4/bind9_dlz environment and are
>>>> now facing high latencies for user/password authentications, especially
>>>> apparent when doing LDAP authentication and group lookups from postfix
>>>> or dovecot.
>>> How many users in your setup ?
>>>> But also the authentication from our file servers, running
>>>> samba3 + winbind, is very slow. When accessing a share for the first
>>>> time or after some inactivity it takes quite a while till folder view
>>>> pops up.
>>> Well there is nothing special in your setup it looks like the one I was
>>> using, and auth was ok.
>>> But I had ~ 30 users in production.
>>> Matthieu.
>> Hello Matthieu,
>> thanks for the fat reply.
>> We have about the same user number.I have migrated our old win2000 AD to
>> samba4 and raised forest and domain level to 2008r2. In my test (esx)
>> environment I have only tested with some clients (WinXP, WinVista, 2k8
>> server) and it seemed to work well, at least authentication, GPOs and
>> sripts did work like before. I did not recognize such delays in my
>> testing environment. Unfortunately I did not test the LDAP stuff.
>> Any idea how to find out where the delay is generated ? What I have
>> observed is that sometimes the samba processes use up a lot of CPU.
> Two approaches come to mind:
> - Use the perf tools
> https://code.google.com/p/kernel/wiki/PerfUserGuide
> - See if you happen to hit the spinner with:
>   gdb -p <samba pid>
>   bt full
>   c
>   (Ctrl-C)
>   bt full
>   c
Hello Andrew,

I will try to follow your two proposed approaches. Unfortunately I have
never used the perf tools before, can you give me some more hints how to
use those in my case ?

Thank you for your kind help.

best regards


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