[Samba] Slow file transfer on ADDC mode

[Dante F. B. Colò]

Hi, 

I have an issue on a Samba 4.5 running as AD DC compiled from source installed on a CentOS 7.3 server upgraded from 4.3 which had the same problem ,file transfers of a single file between Samba and windows machines don't go over 13 MB/s while a transfer over ssh( scp or sftp) and rsync goes over 80 and 100 MB/s respectively, network hardware switches and machines ethernet cards are all gigabit ,i also tried increase log verbosity but didn't see anything wrong, maybe i failed to figure it out , anyway i deployed a Samba on other customer with the same version,build options ,configuration, same OS and had no issues, i'l post here samba build options and smb.conf , any ideas or suggestions ? 

Best Wishes 
Dante 

./configure --jobs=4 -vp --fatal-errors --slow --enable-debug --enable-selftest --with-logdir=/var/log/samba --sysconfdir=/etc --localstatedir=/var/lib/samba --oldincludedir=/usr/local/samba/old_include --mandir=/usr/share/man --with-statedir=/var/lib/samba --with-privatedir=/var/lib/samba/private --with-piddir=/var/run/samba --with-cachedir=/var/cache/samba --with-lockdir=/var/lib/samba/locks --with-logfilebase=/var/log/samba --with-sockets-dir=/var/run/samba --with-configdir=/etc/samba 

[global] 
bind interfaces only = yes 
interfaces = lo em1 
workgroup = SOTOPIETRA 
realm = SOTOPIETRA.LOCAL 
netbios name = S11 
os level = 255 
server string = SOTOPIETRA-PDC 
server role = active directory domain controller 
dns forwarder = 192.168.0.2 
time server = yes 
admin users = leonardo.soares 
ntp signd socket directory = /var/lib/samba/ntp_signd 
server services = s3fs, rpc, nbt, wrepl, ldap, cldap, kdc, drepl, winbindd, ntp_signd, kcc, dnsupdate, dns 
max protocol = SMB3_02 
max log size = 4096 
debug class = yes 
debug prefix timestamp = yes 
log file = /var/log/samba/log.%I 
log level = 1 
printing = bsd 
load printers = no 
printcap name = /dev/null 
disable spoolss = yes 
use sendfile = yes 
smb2 leases = no 
dbwrap_tdb_mutexes:* = yes 
max stat cache size = 65536 
[netlogon] 
path = /var/lib/samba/sysvol/sotopietra.local/scripts 
read only = yes 
browsable = no 
[sysvol] 
path = /var/lib/samba/sysvol 
read only = No 
browsable = no 
[profiles] 
vfs objects = acl_xattr 
map acl inherit = yes 
store dos attributes = yes 
path = /samba/profiles 
writable = yes 
browsable = yes 
csc policy = programs 
[Homedirs] 
vfs objects = acl_xattr 
map acl inherit = yes 
store dos attributes = yes 
path = /samba/homedirs 
writable = yes 
browsable = yes 
[RH] 
vfs objects = full_audit,acl_xattr 
full_audit:prefix = "%u|%I|%P" 
full_audit:success = rmdir unlink rename 
full_audit:failure = rmdir unlink rename 
full_audit:facility = LOCAL0 
full_audit:priority = NOTICE 
map acl inherit = yes 
store dos attributes = yes 
writable = yes 
browsable = yes 
path = /samba/files/rh