samba - Feb 2018 - Difference between root as samba user and other non-root-users?

Hello together,

I am working currently with an installation of CentOS 7.3 and Samba in the 
version 4.4.4. I am setting up a share for Mac-Clients with the required 
vfs-modules catia, fruit and streams_xattr. I also configured two changes 
on the Mac side.

/etc/nsmb.conf

[default]

signing_required=no


/etc/sysctl.conf auf dem Mac:

net.inet.tcp.delayed_ack=0

When I mounted the share with as normal samba user and execute the command 
"time du" on a folder with 50000 files inside I got a time of around 4
seconds. When I do the same with the root as samba user I got the result 
of 1,5 seconds. I created more and more files and repeated the command. 
Root is always faster than a normal samba user. Why?

smb.conf

[global]
netbios name = test
workgroup = testgroup
security = USER
local master = no
dns proxy = no

socket options = TCP_NODELAY

strict allocate = yes
strict locking = no

dead time = 15
max xmit = 65535
min receivefile size = 16384
use sendfile = yes
aio read size = 16384
aio write size = 16384

[example]
comment = ShareBox
path = /media/share
read only = no
create mask = 0777
directory mask = 0777
force create mode = 0777
force create directory mode = 0777
writeable = yes
valid users = root,jones
vfs objects = catia fruit streams_xattr
fruit:resource = file
fruit:metadata = netatalk
fruit:locking = none
fruit:encoding = private
force unknown acl user = Yes

The performance of copy commands is ok. I tested this szenario also with 
windows 7, 10 and another CentOS 7.3 installation. Root as samba user was 
always faster to present me the result of "time du".

Any idea?

Many thanks in advance!

Matthias



Best Regards

Matthias Knigge
R&D File Based Media Solutions

Rohde & Schwarz 
GmbH & Co. KG
Hanomaghof 1
30449 Hannover
Telefon +49 511 67 80 7 213
Fax +49 511 37 19 74
Internet: Matthias.Knigge at rohde-schwarz.com
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