PSODs and the iovDisableIR Setting
One of my customers recently came across an issue where their ESXi hosts were randomly crashing with a PSOD. They had recently applied the latest SPP from HP and the latest ESXi 6.0 patches, and were now occasionally seeing these crashes with messages like "LINT1/NMI (motherboard nonmaskable interrupt), undiagnosed. This may be a hardware problem..." As the PSOD implied, they had called HP support for help, but weren't making much progress. I did some googling and found a really interesting blog post from Jason Whitelock about a recent ESXi update causing HP servers to PSOD . He had come across the exact same issue and had tracked it down to the value of the iovDisableIR setting, which had changed in this latest ESXi update. When he set it back to its original setting, the PSOD issue went away. As VMware explains it, Interrupt Remapping (the technology that's affected by this setting) enables more efficient IRQ routing and thus improves performance...