Having several virtual servers with Windows 2008 R2 at our web hoster (Germany's "1&1", they seem to use Citrix Xen), I have every now and then some servers that hang (RDP login screen hangs forever).
Only turning the server off and on again via the hoster's web control panel helps "resolving" this.
After this reboot, I find an entry in the event log:
Log name: System
Event ID: 5001
The description for Event ID 5001 from source xennet6 cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.
If the event originated on another computer, the display information had to be saved with the event.
The following information was included with the event:
\Device\NDMP1 Citrix PV Ethernet Adapter #0
When looking in the "Uninstall Programs" in Windows I see an entry
"Citrix Tools for Virtual machines".
From pure guessing, I could imagine that this tool may be a cause for the issue.
So I searched Google and Citrix Xen forums to see and information for what this tool is intended and whether it would be safe to remove it.
Unfortunately I found no answer. What I found is this long thread on the Citrix forums, which I do not understand fully.
Therefore my question is:
Is it safe to uninstall "Citrix Tools for Virtual machines" from my Windows 2008 R2 64-Bit Server?
("Save" in terms of "The server still boots and runs normally")
Following the fantastic answer of syneticon-dj, I contacted the 1&1 support, asking about how to fix the server halts. They first suggested to:
- Disable IPv6.
- Delete all not-required network adapters.
Since I already did both without success, I pointed them to this Server Fault posting, asking whether it is safe to upgrade Xen Tools as pointed out in the Rackspace KB article.
They answered something vague like:
"Give it a try, from our point-of-view, nothing should go wrong. If it real helps you have to see afterwards".
So I now have one server updated five days ago with no more errors since then; I updated another server today, no errors there, too.
(I did a snapshot of the server through the 1&1 web UI console before upgrading the tools)
Just as a future reference on how to get the Citrix Tools for Windows:
- Go to the download page on the Citrix server or use this direct download page. (version 6.1 as of writing)
- Find "XenServer-6.1-install-cd.iso" (If you don't find it, here is a direct link that hopefully does not expire).
- Extract the ISO to a folder (e.g. simply double-click the ISO file on Windows 8 or use Iso Buster)
- Find the folder "client_install"
- Copy the content to your Windows 2008 Server.
- Execute "windows-pvdrivers-xenlegacy.exe" by double-clicking.
It also seems that the previously disabled IPv6 got re-enabled by the installation process. So be sure to remove the "Internet Protocol Version 6 (TCP/IPv6)" check box again in the properties of the Citrix PV Ethernet Adapter #0.
There is a new version 6.2 available on this download page.
We solved the issues by moving the server(s) away from the Xen hosting provider to another provider that has real hardware machines. (Google-translated blog article about the details for those interested)