[Samba] Kompas/autocad perfomance

[Владимир Терентьев]

Good afternoon. Performance problems when opening drawings Kompas
V13/autocad 2010 with resource Samba.
When simply copying speed 11.2MB / s. And to read and write to Samba. Next
I mount resource Samba, as a network
ROM for Windows 7 Pro x64. When opening a drawing for editing , there a
large number of small requests . Kompas / autocad not
cache the file, and read his blocks , often and quickly. At this point,
there is a large drawdown performance.
For example : with Windows Server on Windows 7 (client) opens a drawing for
15 seconds , with Samba on Windows 7 PRO x64 drawing opens in 32 seconds.
I thought that perhaps not optimized kernel parameters . And I decided to
check on the KVM server.
If you take a server with KVM, put there Windows 8.1 (+ virtio) and share
the folder , and then put back the drawing , it opens fine.
Do I understand correctly that the OS kernel parameters are normal or KVM
virtualization everything is on the line , bypassing the kernel Host-
system?
How to make the opening a drawing with Samba server sopostovimym with
Windows server?

Linux Fileserver:
Kernel: 3.2.0- 4 -amd64 # 1 SMP Debian 3.2.51-1 x86_64 GNU / Linux
OS ver: Debian Wheezy 7.2
Samba ver: Version: 2:3.6.6-6 + deb7u1 Architecture: amd64

Linux Server with KVM virtualization:
Kernel: 3.2.0- 4 -amd64 # 1 SMP Debian 3.2.51-1 x86_64 GNU / Linux
OS ver: Debian Wheezy 7.2

Clients: Windows 7 PRO x64

Windows Server ( for comparison ): Windows Server 2008 R2 Standart

Samba Config:
socket options = SO_KEEPALIVE TCP_NODELAY IPTOS_THROUGHPUT SO_RCVBUF =
262140 SO_SNDBUF = 262140
read raw = yes
write raw = yes
level2 oplocks = yes
getwd cache = yes
use sendfile = yes
large readwrite = yes
aio read size = 16384
aio write size = 16384

I tried to change the values ​​in the direction of decreasing SO_RCVBUF and
SO_SNDBUF, but it did not help .
I tried to change the version of the protocol on the SAMBA server, but it
did not help .
PS. I know that the SMB protocol is slow, but why the difference with
Widows machine 2 times I do not understand .