Disabletaskoffload

[Su Strawderman]

ifyou use provisioning service in combination with Xen servers also check this key.

HKEY_LOCAL_MACHINESystemCurrentControlSetServicesxenevtchnSetFlags 30000 hex.

This effectively disables TSO and DMA on the Xen Tools.

Ive got some Windows 2k3 and Windows 2k8 VMs running on the Xenserver 5.5 update 2 and Xenserver 5.6.

These settings apply to Xenserver 5.5 update 2?

I did network tests with iperf and had good results, like this:

[ ID] Interval Transfer Bandwidth

[1860] 0.0-10.0 sec 113 MBytes 94.6 Mbits/sec.

Hi Thomas, probably depends on who you are talking to at Citrix. Anyway it have worked for me without reboot. Just keep in mind that you have to run this script every time you add a new VM, because the script is also setting this on the VIF adapter (Virtual).

Once I was able to test and verify that my network was functiioning as expected, I was able to key in on one of your suggestions pertaining to the vCPU assignment. I had never read or came across anything mentioning this very important detail until you contacted me.

I have 3 xenservers running 5.5 update 2. I have 6 2003 R2 x86 vms running xenapp 4.5. I have enabled the disabletaskoffload a while back per citrix recommendation> I cant not find the documentation of what my issue was i just have a vague memory. Lately we have been having extreme slowdowns. Like 30 seconds to click start type of stuff. Other times its less significant. All theses vms boot from an equallogic san. We can not find any hints of performance issues on the SAN or iscsi switches. I am really at a loss. Does this sound like it could be related to the issues your address with the script? This has been beating me up for a few months now. its coming to a head where it is causing so many productivity issues i am considering rebuilding a physical farm. It often happens to a few servers at a time. the vms usually do not report unusual CPU or memory useage during the slowness. I am at a loss.

Hi Mike, hope business is going great for you, see you in Anaheim 2013? Did some troubleshooting a couple of weeks ago regarding slow performance on HP BL 465C G7 blades, having an open ticket with Citrix support. When doing research if found this awesome post discussing what your asking about. -network-tuning/

Quite new to scripting. How do I get your script into a XenServer console to be able to run it? Also just read the website you linked to in your last post and using ethtool -k i can see that i still have rx and tx checksum on. Need to get checksum off for both PIF and VIF as we have some slow networking issues on the XenServers and VMs.

In our office we are in the process of upgrading the Autocad version from 2009 to 2011. During Installation the server (VM) and the Host both completely hangs off while changing the installation medias (out of total 4 medias, only the first media is running good). The full host is to be powered off and powered on, when Installation starts from the beginning and as usual the hanging problem persists while changing the media.

Hi Eirik, we recently upgraded our xenservers to xenserver 6.2, now the Network Performance Problems found their way back to our vm s. When we run the script to disable rx tx and gso -offloading just nothing habbened. When we set the taskoffloading to off with ethtool -k it seems to be off, but when we restart our Servers ethtool -K tells us that the taskoffloading is on again. Is there another way to disable the offloading configurations. We use xenserver 6.2 xenapp 6.5 and xendesktop 7. Thank you for your Help and your Website.

We receiving slow citrix performance, installed citrix receiver and all of them from Win7 laptops, but much faster when using desktop machine, and it happens mostly during work time, checked both configuration laptop and desktop same, any expectation?

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