[Samba] 10GE performance issues

[Martin Markert]

Hi,
we have network performance issues with Samba (Version 4.2.7-SerNet-RedHat-19.el6) on one of our servers. The maximum throughput from client to server is 110 MB/s (read/write) under Windows 7 x64 (single 10GE NIC). When using NFS on a different Linux workstation we're getting much higher rates, around 500-700 MB/s. I still can't find the problem.

Setup server:
CentOS 6.6
Samba 4.7.2
Mellanox 10GE NIC with LACP bonding
local attached storage: XFS, 1,5 GB/s read/write

[global]

     workgroup = ARRI
     server string = Samba Server Version %v
     netbios name = BARBARELLA

     log file = /var/log/samba/%m_%a_%R.log
     max log size = 50
     log level = 1

    security = ads
    realm = ARRI.DE
    encrypt passwords = Yes

    winbind enum users = Yes
    winbind enum groups = Yes
    winbind use default domain = Yes
    winbind nested groups = Yes
    winbind separator = +
    winbind offline logon = false

    idmap config * : backend = tdb
    idmap config * : range = 600-799
    idmap config ARRI:backend = ad
    idmap config ARRI:range = 800-19999
    idmap config ARRI:schema_mode = rfc2307

     allow trusted domains = Yes
     server signing = mandatory
     client signing = mandatory
     client use spnego = Yes
     ntlm auth = Yes
     lanman auth = No

     preferred master = no

     printcap name = /etc/printcap
     load printers = no


Do you have any suggestions?

Kind regards,
Martin
--
Martin Markert
Westendstr. 89
80339 München