Specifications

Hardware Support
Red Hat Virtualization supports multiprocessor systems and allows you to run Red Hat
Virtualization on x86 architectured systems with a P6 class (or earlier) processors like:
• Celeron
• Pentium II
• Pentium III
• Pentium IV
• Xeon
• AMD Athlon
• AMD Duron
With Red Hat Virtualization, 32-bit hosts runs only 32-bit paravirtual guests. 64-bit hosts runs
only 64-bit paravirtual guests. And a 64-bit full virtualization host runs 32-bit, 32-bit PAE, or
64-bit guests. A 32-bit full virtualization host runs both PAE and non-PAE full virtualization
guests.
The Red Hat Enterprise Linux Virtualization kernel does not support more than 32GB of memory
for x86_64 systems. If you need to boot the virtualization kernel on systems with more than
32GB of physical memory installed, you must append the kernel command line with mem=32G.
This example shows how to enable the proper parameters in the grub.conf file:
title Red Hat Enterprise Linux Server (2.6.18-4.elxen)
root (hd0, 0)
kernel /xen.gz-2.6.18-4-el5 mem=32G
module /vmlinuz -2.6.18-4.el5xen ro root=LABEL=/
module /initrd-2.6.18-4.el5xen.img
PAE (Physical Address Extension) is a technology that increases the amount of physical or
virtual memory available to user applications. Red Hat Virtualization requires that PAE is active
on your systems. Red Hat Virtualization 32 bit architecture with PAE supports up to 16 GB of
physical memory. It is recommended that you have at least 256 megabytes of RAM for every
guest you have running on the system. Red Hat Virtualization enables x86/64 machines to
address up to physical 64 GB. The Red Hat Virtualization kernels will not run on a non-PAE
system. To determine if a system supports PAE, type the following commands:
grep pae /proc/cpuinfo
Chapter 3.
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