Additions : Replace Samba 3 to Samba 4:
In simple:
Download compiled bin’s: https://drive.google.com/file/d/0B_6OlQ_H0PxVVmNFWXVHYTZ3XzQ/edit?usp=sharing
apt-get install samba
service samba stop
tar xvfz samba4_binary.tar.gz -C /usr/sbin/
service samba start
In /etc/samba/smb.conf edit/replace:
security = user
lanman auth = no
main protocol = NT1
encrypt passwords = truesocket options = IPTOS_LOWDELAY TCP_NODELAY SO_KEEPALIVEwrite cache size = 2097152
use sendfile = true
getwd cache = ye
Result:
Download speed: 60-70 MB/s*
Upload speed: 30-40 MB/s*
* @ 1 GB/s network via Samba (CIFS, Windows shares)