6.4. ia64 Architecture

When attempting to create a fully-virtualized guest, the hypervisor no longer hangs due to memory shortage when a large amount of memory is allocated to the guest. This version of the hypervisor automatically takes care of allocating needed memory for hypervisor overhead.

Virtualization on this architecture can now support guests with RAM beyond 65,434 MB.

By default, the Itanium dom0 virtualized kernel can now boot with up to 4 CPUs and a maximum system memory of 4GB. In previous releases, the Itanium dom0 virtualized kernel only booted with 1 CPU and a maximum system memory of 500MB by default.

In addition to this, the Itanium dom0 virtualized kernel allocates as much system memory as it can (up to the 4GB maximum by default, or up to the maximum amount specified with the dom0_mem= parameter) while avoiding memory starvation on the hypervisor.

Migrating paravirtualized guests through xm migrate [domain] [dom0 IP address] does not work.

Creating a guest more than 1,000 times will cause dom0 to reboot suddenly. Red Hat recommends that you pre-empt this by rebooting dom0 before the domain ID of any guest reaches 1000.

If you encounter a guest installation failure, Red Hat recommends that you restart the xend daemon before attempting to install a new guest.

On some Itanium systems configured for console output to VGA, the dom0 virtualized kernel may fail to boot. This is because the virtualized kernel failed to properly detect the default console device from the Extensible Firmware Interface (EFI) settings.

When this occurs, add the boot parameter console=tty to the kernel boot options in /boot/efi/elilo.conf.

On some Itanium systems (such as the Hitachi Cold Fusion 3e), the serial port cannot be detected in dom0 when VGA is enabled by the EFI Maintenance Manager. As such, you need to supply the following serial port information to the dom0 kernel:

These details must be specified in the append= line of the dom0 kernel in /boot/efi/elilo.conf. For example:

append="com1=19200,8n1,0x3f8—quiet rhgb console=tty0 console=ttyS0,19200n8"

In this example, com1 is the serial port, 19200 is the speed (in bits/second), 8n1 specifies the number of data bits/parity settings, and 0x3f8 is the io_base address.

Virtualization does not work on architectures that use NUMA. As such, installing the virtualized kernel on systems that use NUMA will result in a boot failure.

Some installation numbers install the virtualized kernel by default. If you have such an installation number and your system uses NUMA (or cannot disable NUMA), deselect the Virtualization option during installation.

Currently, live migration of fully virtualized guests is not supported on this architecture. In addition, kexec and kdump are also not supported for virtualization on this architecture.