[Samba] Slow write performance CIFS mount

[Trenta sis]

Hi,

I have detected a very low performance with cp command or any write
with CIFS mount (Netapp Storage), <15mb/s. Read performance is similar

Local disk perofrmance is  correct >100mb/s

fstab entry is :
//netapp/resource$/folder  /mnt/test cifs
username=u,password=p,domain=dom,iocharset=utf8,uid=1001,gid=1000,dir_mode=0700,file_mode=0700,auto

Server is SLES 12 SP3 with latest updates and samba
samba-client-32bit-4.6.13+git.72.2a684235f41-3.21.3.x86_64
cifs-utils-6.5-9.3.2.x86_64

Any suggestion?

Thanks