Saturday, April 21, 2012

How to disable Intel VT-d on ESX

When using Interrupt Remapping on some servers, you may experience vHBAs and other PCI devices stop responding in ESXi 6.0.x, ESXi 5.x and ESXi/ESX 4.1

This issue should be solved by server vendors releasing fixed BIOS version but if there is not a fix available you can use following workaround until new BIOS is released.

Disabling Intel VT-d Interrupt Remapping:

ESX/ESXi 4.1:
esxcfg-advcfg -k TRUE iovDisableIR

ESXi 5.0:
esxcli system settings kernel set --setting=iovDisableIR -v TRUE

Disabling all VT-d features:
Advanced setting VMkernel.Boot.noIOMMU = unchecked = 0

For more info look at 


rajib said...

Hi David,

will the configuration impact the software SMI control port 0xb2?


David Pasek said...

To be honest I don't know what would be impact on SMI however this is just a workaround in situations when Interrupt Remapping causing some issues. In other words, you should not use it by default anyway.