I have a Windows server 2008 VM running in Australia and another one in the USA.
They are connected over the Internet via an IPSec VPN, typical latency is around 160ms
When I attempt to transfer files between the two servers the max speed I get is around 500Kbs. This is well below the speeds I should reach. This is using FTP or normal windows file transfers.
Now, I also have multiple Linux based VMs running in the same virtual environment as the Windows ones, and when I transfer between the Linux machines I can get 5MB/s transfer rate. So please do not blame this speed on 'the network' or the virtual environment because clearly I can get much faster transfer.
So, I have mucked around with numerous registry settings on the windows servers, from this link
I have done EnablePMTUDiscovery, Tcp1323Opts, TcpWindowSize, and also disabled tcp/ip auto tuning with the 'netsh interface tcp set global autotuning=disabled' command. Nothing I do makes any difference.
Wireshark captures don't so any retransmits or TCP resets, or really anything out of the ordinary.
This seems to be common issue, there are numerous threads on this forum about this topic, and also on other sites... I'm hoping someone can assist here, are there any other suggestions?
Remove the QoS of the NIC and test again.
With QoS the % reserved for the system is really high. In exemple if you use product like ghost to send the image live to another share, I was sending at like 4 mbps over the LAN on a 100mbps NIC with the QoS.
- Edited by Yagmoth555MVP, Moderator Tuesday, January 22, 2013 3:31 AM
- Edited by Yagmoth555MVP, Moderator Tuesday, January 22, 2013 3:42 AM
In the wireshark does the server try to use the wan for something else, like windows update.
else I would erase the nic to let it re-create, and then test again in the LAN directly with a linux OS you did (in ftp in worst case) to stress the NIC's driver a bit.
It's not a VM that got a P2V done on them ? like hp proliant server got the teaming software that cause a lot of network issue if you dont manually desactivate the service.
Did you test linux to a windows server ? to target the faulty windows's server
- Edited by Yagmoth555MVP, Moderator Tuesday, January 22, 2013 4:12 AM
I have face same issue once which solve my issue. What i did was I went to the advanced properties for network card and disabled every thing from there like flow control, Jumbo packtes, ipv4 offload settings and there are lot settings I made them disabled on both the ends and it went fine try and do let me know.
Did you did the test to find what windows is slow ?
US <--> Austria
Linux <--> Windows
Windows <--> Linus
If not a QoS setting in the router, It can only be a driver problem, thus it can't be a error in the vm tool and the xenserver tool at the same time... (Never forget that if you did like a upgrade from Xenserver 5.6 to 6, if you didn't updated the tool in the VM, the driver will be not optimized at all. Xenserver is hard on retro-compatibility( so it can be a lot of things)
- Edited by Yagmoth555MVP, Moderator Wednesday, January 23, 2013 1:43 AM
That doc could maybe help.. http://download.microsoft.com/download/3/2/A/32A70368-1457-4972-8CDD-08A496198361/Perf-tun-srv-R2.docx and check the network section, or please check that doc; http://support.citrix.com/servlet/KbServlet/download/29413-102-692918/XA%20-%20Windows%202008%20R2%20Optimization%20Guide.pdf and check for SMBv1 or SMBv2's tunning registry key.
With all my answer, I still rethink to your problem and I have big difficulty to not think it's a QoS in the router. Bind the same network card to your VM as the liniux's one, and put the same IP to rule that out maybe
Does the copy is fast in the LAN ? 500kbs, even with bad driver, is not even .1% of your NIC in XenServer (tagged 2GiG in the OS) and do you binded the same network adaptor as your linux VM ?