[Samba] samba 4 DC slow users bulk load

Nikos Mitas nkmitas at gmail.com
Mon Oct 7 13:52:56 MDT 2013

Hello again,

all three samba4 DC's have 16 GB RAM each and 2 sockets with 4 cores each
(total 8 cores each) the three DC's and the identity manager are in the
same VLAN.

but today i noticed that during bulk load only one core is busy 100% and
the rest are idle. i was unable to run samba under TDB_NO_FSYNC=1 today.
maybe tomorrow.

this is the link for the perf.data file:
this is my smb.conf:

# Global parameters

workgroup = NKMITAS
realm = nkmitas.gr
netbios name = SAMBA4DC3
server role = active directory domain controller
server services = s3fs, rpc, nbt, wrepl, ldap, cldap, kdc, drepl, winbind,
ntp_signd, kcc, dnsupdate

path = /usr/local/samba/var/locks/sysvol/nkmitas.gr/scripts
read only = No

[sysvol] path = /usr/local/samba/var/locks/sysvol
read only = No

thanks for your help
On Oct 6, 2013 11:49 PM, "Andrew Bartlett" <abartlet at samba.org> wrote:

> On Sun, 2013-10-06 at 13:48 +0300, Nikos Mitas wrote:
> > Hello,
> >
> > i have successfully installed samba 4 on three vmware VM's and everything
> > works fine (join pc to domain, user login, dns updates, ntp),
> > but i am facing some performance problems during users bulk loading.
> > my environment:
> >
> > 1st DC: RedHat Linux v6.4,samba 4.1rc4,dns 9.9.3P2,ntp
> > 2nd DC:RedHat Linux v6.4,samba 4.1rc4,dns 9.9.3P2,ntp
> > 3rd DC:RedHat Linux v6.4,samba 4.1rc4,ntp
> >
> >
> > to bulk load the users (around 20.000 accounts) i am using IBM Tivoli
> > Identity Manager to automatically create the AD accounts into Samba
> > but the performance is poor. 120 users per hour at most.
> >
> > Any ideas what to check or what needs to be tuned?
> We need to work out what specifically is slow, so we can deal with it.
> If you can capture the ldap server task under 'perf record -g -p PID'
> that might give some clues.  It shouldn't take 30 seconds to add a user,
> but at this size many O(n^2) things blow up badly, and we may need to
> re-investigate better approaches in some cases.
> Also, ensure you have plenty of memory, and for the period of the
> import, run samba under TDB_NO_FSYNC=1.  This makes samba unsafe against
> a poweroff event (equivalent to linking with libeatmydata), so don't use
> this in production, but it will make things much, much faster for the
> initial import.
> Andrew Bartlett
> Andrew Bartlett
> --
> Andrew Bartlett
> http://samba.org/~abartlet/
> Authentication Developer, Samba Team           http://samba.org
> Samba Developer, Catalyst IT                   http://catalyst.net.nz

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