XenServer 6.X random crashes

In a previous post I wrote that I had some XenServers which where randomly rebooting and I solved it by disabling the “Write-Cache Battery Override” but after two weeks the servers are again rebooting randomly. After contacting my support contact at our reseller he send me a link (http://support.citrix.com/article/CTX136517) to a Citrix knowledge base which mentions that the problem is in the Intel 5500/5520/X58 chipset. When uploading the XenServer System Status report to Auto Support this issue will be detected. 

When looking at the Knowledge Base article I executed the following commands:

# xl debug-keys V
# xl dmesg | grep “Interrupt Remapping”

Interrupt Remapping

The commands displays that Interrupt Remapping is supported, now we have to Disable Interrupt Remapping. This can be done by adding the following Xen boot parameter “iommu=no-intremap” to the /boot/extlinux.conf.

I used the following command which adds it to the Xen boot parameters for you without having to manually edit the /boot/extlinux.conf file:

/opt/xensource/libexec/xen-cmdline –set-xen iommu=no-intremap

This solves out problem and now the servers are stable.