For those of you that have tried installing Fedora 9 x86_64 on the latest Intel Quad Core chipset, you might find the kernel a bit pissy depending on your architecture. We recently got in a shipment of brand spanking new HP dc7800 workstations, only to find out that the kernel shipping with F9 is a royal pain in the ass. Earlier I posted this story about power management issues and the SATA drive not being found in the i386 install. Now with the x86_86 version, a new problem was found.

Upon loading the kernel in quiet mode (default install and live cd), it hangs after the loading kernel screen. With verbose mode on we found that it would hang indefinitely at this message:

IOMMU: Setting identity map for device 0000:00:1a.1 [xdefd6000 - 0xdefd7000]

Thankfully, there are two easy ways around this. The first consists of adding "intel_iommu=off" to the kernel boot line. For those of you that aren't Linux savoy, all you need to do is boot into GRUB and append that phrase to the end of the kernel line (or edit your grub.conf).

The second solution is even easier. Once you boot with the first solution, update Fedora 9 to the latest available packages. In the update will be the 2.6.25.6 kernel which has the proper code for this architecture! We didn't see anymore issues after this point, so you can remove the kernel append line if you still have it in your grub.conf